Method for regulating and controlling dissolved oxygen and potential dechlorination through cooperation of ultrasonic waves and sulfite solution

Abstract

The invention discloses a method for regulating and controlling dissolved oxygen and potential dechlorination through cooperation of ultrasonic waves and a sulfite solution, and relates to the technical field of solution purification and impurity removal. Comprising the following steps: dissolving sulfite with deionized water to obtain a sulfite solution; respectively heating the sulfite solution and the chlorine-containing solution to be treated; after heating is finished, slowly adding the sulfite solution into the chlorine-containing solution to be treated at a constant speed, stirring and reacting, and simultaneously adopting ultrasonic wave for synergistic reaction; after the reaction is finished, carrying out vacuum filtration to obtain filtrate and filter residues; copper ions in the solution are reduced into cuprous ions by the sulfite ions, and cuprous chloride precipitates are generated by the cuprous ions and chloride ions, so that the removal of chlorine is realized. The dissolved oxygen content and the oxidation-reduction potential of the system are reduced by means of ultrasonic synergistic enhancement, temperature rise and the like, and cuprous chloride is prevented from being dissolved inversely while the reducing capacity of the sulfite solution is enhanced. Ultrasonic waves play multiple roles in the process, including reaction resistance reduction, mass transfer acceleration, reaction temperature maintenance, reaction interface updating and the like.

Description

Technical Field

[0001] The invention relates to the technical field of solution purification and impurity removal, and in particular to a method for regulating dissolved oxygen and potential dechlorination by using ultrasound in conjunction with a sulfite solution. Background Art

[0002] Hydrometallurgy is the mainstream process for the production of refined zinc. The raw materials for zinc smelting come from a wide range of sources, mainly zinc sand, zinc oxide, various smoke and other zinc-containing materials (such as zinc slag, etc.). During the hydrometallurgy process, most of the chlorine in the raw materials enters the leachate. High concentrations of chloride ions have a great harm to the electrolytic process of zinc. When the chlorine concentration in the system exceeds 200 mg / L, chloride ions will corrode the anode plate and cause corrosion products to deposit at the cathode, affecting product quality. In addition, high concentrations of chloride ions accelerate the corrosion of stainless steel equipment in the system. More importantly, it causes large amounts of acid mist at the electrolysis site, deteriorates the environment at the production site, and affects production operations. Domestic and foreign manufacturers have set strict limits on the chlorine content in the electrolytic solution to meet the standards for the electrolyte. Therefore, the removal of chlorine is particularly necessary for the smooth production of hydrometallurgy.

[0003] At present, the commonly used methods for removing chloride ions include chemical precipitation, ion exchange, oxidation, thermal evaporation and membrane processes. The chemical precipitation method is simple in process and the raw materials are readily available. It is a method that is widely used in industry. It includes silver chloride precipitation dechlorination method, bismuth oxychloride precipitation dechlorination method and copper slag dechlorination method. Among them, the silver chloride precipitation dechlorination method and bismuth oxychloride precipitation dechlorination method have high costs and are limited in their industrial application. The copper slag dechlorination method is based on the reaction of copper with divalent copper ions and Cl in zinc sulfate solution. - Interact with each other to form a precipitate whose main component is cuprous chloride. However, due to the different process characteristics and resource conditions of each enterprise, the actual conditions for the control of copper slag dechlorination process are also different. The large loss of copper slag and high cost are the main problems faced by the traditional copper slag dechlorination process. The reason is that;

[0004] (1) Cuprous chloride dissolution. The copper slag dechlorination process is to improve the Cu 2+ Concentration: In the dechlorination process, air stirring or the addition of oxidants such as MnO2 are often used to accelerate the dissolution of copper.

[0005] 2H2SO4+2Cu+O2=2CuSO4+2H2O#(a)

[0006] 2H2SO4+Cu+MnO2=MnSO4+CuSO4+2H2O#(b)

[0007] Although adding oxidants can accelerate the oxidation of copper slag and improve the system Cu 2+concentration, shortening the dechlorination operation time, but air stirring or adding oxidants such as MnO2 will also increase the oxidation amount of iron in the system, resulting in Fe 3+ The increase in content causes the dechlorination product cuprous chloride to dissolve back, reducing the dechlorination efficiency.

[0008] 2Fe 3+ +Cu2Cl2=2Cu 2+ +2Fe 2+ +2Cl - #(c)

[0009] (2) The copper metal in the copper slag has low activity. The dechlorination of copper slag to produce cuprous chloride precipitation mainly relies on the reaction between divalent copper ions and elemental copper. The reaction rate is affected by kinetic factors, especially the activity of metallic copper. The activity of newly formed Cu is much greater than that of Cu in the copper slag. However, in the actual production process, due to the different storage time of copper slag and the different oxidation degree of copper slag, the activity of elemental copper decreases when the copper slag is recycled, and its content and oxidation state Cu are different. 2+ The content of is difficult to accurately measure and control. This ultimately leads to unstable dechlorination effect when copper slag is recycled, and the operating parameters are difficult to control. A large amount of copper sulfate and copper powder need to be added to create the conditions for dechlorination of copper slag, resulting in large copper slag loss and high cost. Therefore, it is very important to find an economical and efficient method for purifying chloride ions.

[0010] In recent years, many new chloride ion precipitation agents have been gradually developed and utilized, among which sulfite is widely used in the field of industrial water treatment and purification. Among them, patent application number: 201410648939.9 discloses a method for removing chloride ions from a copper sulfate solution. Solid sodium sulfite and sodium carbonate are added to a chloride-containing copper sulfate solution to adjust the pH value and potential of the solution so that it reaches a specific range in which Na2[CuCl3] can exist stably. Subsequently, the supernatant is separated from the mixed solution and copper powder is added. In this step, the Na2[CuCl3] in the supernatant reacts with the copper powder to generate a water-insoluble cuprous chloride precipitate. In this technical solution, the main function of sodium sulfite and sodium carbonate is to adjust the reaction environment and create suitable conditions for subsequent reactions. The removal of chloride ions still depends on the neutralization reaction. It should be noted that when solid sodium sulfite is directly put into an acidic environment, it is easy to react with sulfuric acid to produce a large amount of sulfur dioxide gas, causing gas overflow. At the same time, this addition method may cause significant fluctuations in the local pH value, thereby increasing the risk of other side reactions. Patent application number: 202111177759.3, discloses a method for removing chlorine from hydrometallurgical zinc electrolyte by reducing and purifying zinc sulfite. In this scheme, copper ions are reduced to cuprous ions and react with chloride ions in the electrolyte to form cuprous chloride precipitates, and the amount of cuprous chloride precipitates generated is used as the basis for determining whether the reaction has reached the end point. The solubility product constant (Ksp) of zinc sulfite is 1.46×10 -10, the mass concentration of zinc sulfite solution at room temperature (25°C) is 3.15g / L, which is a slightly soluble substance. The mass concentration of zinc sulfite solution used in this scheme is 20g / L, of which the incompletely dissolved zinc sulfite solids can account for up to 84.25%, which greatly reduces the activity of zinc sulfite in the solution. In its embodiment, copper sulfate solution and zinc sulfite solution are added in equimolar amounts, wherein the mass concentration of copper sulfate solution at room temperature (25°C) is 203g / L, which is a readily soluble substance. In order to achieve the addition of equimolar amounts of zinc sulfite and copper sulfate, a zinc sulfite solution with a volume much larger than that of copper sulfate solution needs to be added. On a physical level, this process can lead to a decrease in the chloride ion concentration of the chlorine-containing electrolyte. The removal of chloride ions may be the result of the combined action of zinc sulfite solids, zinc sulfite solution participating in the dechlorination reaction, and zinc sulfite and copper sulfate solution diluting the zinc sulfate solution. The reaction in which zinc sulfite solid participates is a solid-liquid reaction. Due to the slightly soluble characteristics of zinc sulfite, the precipitate of cuprous chloride, a dechlorination product, may coat its surface during the dechlorination process to hinder the reaction, resulting in low utilization of zinc sulfite. If the above situation occurs, the main effective reaction in its system is a liquid phase reaction in which zinc sulfite solution participates. In order to achieve a better removal effect in a short time, a large amount of zinc sulfate solution needs to be added to increase the effective zinc sulfite concentration that actually plays a dechlorination role, and the dilution effect of zinc sulfate solution is enhanced while increasing the volume of the solution. And the method of judging the end point of the reaction by relying on the amount of precipitation is not accurate enough, which may lead to excessive addition of zinc sulfite solution, further diluting the zinc sulfate solution and affecting the detection results of chloride ions. In this scheme, the zinc sulfite solution is mainly derived from the by-product of the zinc smelter, its access channels are limited, and there are specific requirements for the zinc smelting process. In addition, the patent scheme does not involve effective measures to prevent cuprous chloride from dissolving back and improve the reaction efficiency. The above reasons limit the method to be only applicable to specific fields and are not generally applicable. Summary of the invention

[0011] In view of the problems existing in the prior art, the present invention proposes a method for regulating dissolved oxygen and removing chlorine by potential by using ultrasound and sulfite solution. The purpose is to reduce the content of dissolved oxygen to achieve potential regulation and introduce ultrasound activation to generate sulfite free radicals (SO3 ·- ; E = 0.63V), hydrated electrons (eaq - ; E = -2.9V), hydrogen free radicals (·H; E = -2.3V), etc., to enhance the reducing ability of the sulfite solution, prevent the oxidation and dissolution of the dechlorination products, promote the reaction, and shorten the reaction time. This method effectively solves the technical problems of the conventional copper slag dechlorination process, such as the difficulty in accurately controlling the process parameters, low dechlorination efficiency, and easy dissolution of the dechlorination products.

[0012] To achieve the above object, the present invention provides a method for regulating dissolved oxygen and dechlorination by using ultrasound in combination with a sulfite solution, comprising the following steps:

[0013] (1) dissolving sulfite in deionized water to obtain a sulfite solution;

[0014] (2) heating the sulfite solution and the chlorine-containing solution to be treated respectively;

[0015] (3) After the heating is completed, the sulfite solution is slowly and uniformly added to the chlorine-containing solution to be treated, and stirred for reaction, and ultrasonic waves are used to strengthen the reaction, and after the reaction is completed, a purified and dechlorinated liquid is obtained;

[0016] (4) performing solid-liquid separation on the purified and dechlorinated liquid to obtain a filtrate and a filter residue; and performing vacuum drying on the filter residue to obtain a cuprous chloride precipitate residue.

[0017] Furthermore, the concentration of the sulfite solution in step (1) is 0.05 to 0.13 mol / L.

[0018] Furthermore, the sulfite in step (1) is one of sulfur dioxide fume, sodium sulfite, ammonium sulfite or calcium sulfite.

[0019] Furthermore, the temperature in step (2) is increased to 50-90°C.

[0020] Furthermore, when ultrasound is used to intensify the reaction in step (3), the ultrasound conditions are: frequency 20-30 kHz, power 100-120 W / L.

[0021] Furthermore, during the stirring reaction in step (3), the SO3 2- / Cl - The molar ratio is 0.5-2:1; Cu 2+ / Cl - The molar ratio is 1 to 2:1, and the reaction time is 20 to 50 minutes.

[0022] Furthermore, the stirring rate in step (3) is 100 to 150 r / min.

[0023] Furthermore, the drying temperature in step (4) is 60-65°C.

[0024] Specifically, sodium sulfite and other sulfites can reduce copper ions to cuprous ions due to their reducing ability. The cuprous ions combine with chloride ions to form cuprous chloride precipitates to achieve the purpose of removing chloride ions. Dissolved oxygen is one of the main oxidants in water bodies. When its content decreases, the oxidizing ability of the water body decreases, resulting in a decrease in the redox potential value. By utilizing sulfur dioxide, reducing sulfites such as sodium sulfite and calcium sulfite can react with dissolved oxygen to form sulfates. This process will reduce the dissolved oxygen content in the system. At the same time, an increase in temperature will reduce the dissolved oxygen saturation value, reduce the viscosity of water and the thickness of the liquid film, and increase the diffusion coefficient and the total transfer coefficient of oxygen, which will lead to a decrease in the redox potential even when other conditions remain unchanged. Sulfites dissolve in water to release reducing free radicals (SO3 ·- ,e aq - ,·H, etc.), among which SO3 ·- The existence form of sulfur oxides is closely related to the dissolved oxygen content in the system. When the system lacks dissolved oxygen, sulfur oxides mainly exist in the form of SO3 ·- In the form of SO3 2- At lower pH (<10) it is converted to HSO3 - , and the above process is accompanied by strong reducing free radicals (e aq - ,·H) is generated.

[0025]

[0026] By reacting sulfite with dissolved oxygen and increasing the temperature of the sulfite solution, the sulfoxide free radical can be converted into SO3 ·- exists in the form of e aq - ,·H and other strong reducing free radicals, reduce the overall potential of the sulfite solution, and strengthen the sulfite solution to Cu 2+ Reduction to Cu + While improving the reducing ability, it also prevents cuprous chloride from dissolving back. The slow addition of sulfite in the form of a solution can avoid excessive local pH changes that cause a large amount of sulfur dioxide to overflow, thereby improving the operating environment; the cavitation effect and mechanical effect of ultrasound have the ability to accelerate mass transfer, which can increase the reaction rate and shorten the reaction time. The interior of the cavitation bubble is a high-temperature and high-pressure environment. In this environment, water vapor sonolysis generates highly reducing ·H, which enters the solution as the bubbles burst, lowering the overall potential of the solution and showing stronger reducing properties. The thermal effect of ultrasound can increase the temperature of the chlorine-containing solution to be treated, help reduce the dissolved oxygen in the system, and allow the sulfoxide free radicals to be converted to SO3 ·- While existing in the form of sulfite solution, it reduces the temperature difference with the sulfite solution, reduces the reaction resistance and increases the reaction speed.

[0027] Wherein, step (3) undergoes the following reaction:

[0028]

[0029] This study controls the potential of the solution and the existence form of sulfoxide free radicals by adjusting the temperature and using ultrasonic technology to ensure that the entire reaction system is in a low-oxygen, low-potential and highly reducible state. This environment not only strengthens the reduction reaction, but also effectively prevents the back dissolution of cuprous chloride. The specific value of the potential of the sulfite solution in this method is between -280mv and -1200mv. The potential of the sulfite solution at different temperatures is shown in Table 1:

[0030] Table 1 Potential values ​​of sulfite solutions at different temperatures

[0031]

[0032] The advantages or beneficial effects of the above technical solution include at least:

[0033] (1) The present invention uses a sulfite solution as a reducing agent, which is slowly and uniformly added to the chlorine-containing solution to be treated. The reaction process is mainly a liquid phase reaction, which has the characteristics of short reaction time and rapid reaction, and avoids the overflow of sulfur dioxide gas. By increasing the temperature of the sulfite solution, its dissolved oxygen content and potential can be reduced, the reducing property can be enhanced, and the temperature difference with the chlorine-containing solution to be treated can be reduced, thereby reducing the reaction resistance. Compared with the copper slag used in the copper slag dechlorination method in the prior art, the composition of the sulfite solution is relatively simple, and less impurity ions are introduced. Among them, the sulfur dioxide flue gas itself has a high temperature and no impurity ions are introduced. The cuprous chloride precipitate generated by the reaction contains less impurity elements, which is conducive to subsequent recycling.

[0034] (2) The present invention utilizes ultrasonic activation to generate reducing free radicals, strengthens the reducing ability and maintains the reducing environment; ultrasonic waves propagate in the solution to induce cavitation and mechanical action. Mechanical action can form effective stirring in the solution, promote mass transfer, and increase the reaction speed; the cavitation bubbles generated by cavitation burst and release the internal high temperature to increase and maintain the reaction temperature, create a suitable reaction environment, and increase the reaction depth; the cavitation bubble burst generates a strong jet in the chlorine-containing solution to be treated, which helps to promote the renewal of the reaction interface, enhance the reaction activity, and improve the chlorine removal efficiency, so that the chloride ion removal rate reaches more than 95%.

[0035] (3) The present invention utilizes ultrasound to enhance the chlorination by synergistically regulating the potential of a sulfite solution. Compared with the copper slag used in the copper slag dechlorination method in the prior art, sulfite has a lower price and is added in a smaller amount, which not only reduces costs but also avoids the back dissolution of the dechlorination product, thereby obtaining better economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the XRD spectrum of the purified slag in Example 1 of the present invention;

[0037] Figure 2 is a SEM spectrum of the purified slag in Example 1 of the present invention;

[0038] Figure 3 is the free radical spectrum of the sodium sulfite solution in Example 1 of the present invention; DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limitations of the present invention. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0040] The composition of the chlorine-containing pre-purification solution of all the following examples is shown in Table 2:

[0041] Table 2 Elemental composition of chlorine-containing purification liquid before

[0042]

[0043] Example 1

[0044] A method for enhancing chlorine removal by using sulfite solution potential regulation and ultrasonic wave enhancement, the specific steps are as follows:

[0045] (1) Press SO3 2- :Cu 2+ :Cl - Dissolve 13.86 g of sodium sulfite in a molar ratio of 1.1:1.4:1 and heat to 90°C;

[0046] (2) Take 1 L of the chlorine-containing solution to be treated and heat it to 90°C;

[0047] (3) adding 0.11 mol / L sulfite solution to the chlorine-containing solution to be treated at a uniform speed and slowly, and performing ultrasonic enhanced reaction for 85 min at a temperature of 90° C., a stirring speed of 150 r / min, an ultrasonic power of 100 W, and an ultrasonic frequency of 20 kHz, and performing solid-liquid separation to obtain a purified dechlorinated liquid and a reaction precipitate residue; and vacuum drying the reaction precipitate residue at 65° C. to obtain a cuprous chloride precipitate residue.

[0048] (4) The content of the liquid after purification and dechlorination is shown in Table 3. The chloride ion removal rate is 97.63%

[0049] Table 3 Elemental composition of the liquid after purification and dechlorination

[0050]

[0051] Comparative Example 1

[0052] The difference between this comparative example 1 and Example 1 is that: in step (1), the sodium sulfite solution is heated to 50°C and in step (2), the chlorine-containing pre-purification solution is heated to 50°C; the chlorine ion content of the purified and dechlorinated solution in this comparative example is 1.04 g / L, and the chlorine ion removal rate is 70.66%.

[0053] The experimental results show that increasing the temperature of sodium sulfite solution can reduce the potential of sodium sulfite solution, which has obvious advantages in improving the removal rate of chloride ions.

[0054] Comparative Example 2:

[0055] The difference between this comparative example 2 and example 1 is that: step (3) does not include ultrasonic external field enhancement; the chloride ion content of the liquid after purification and dechlorination in this comparative example is 0.83 g / L, and the chloride ion removal rate is 76.59%.

[0056] The experimental results show that ultrasound can enhance the reaction process and promote the removal of chloride ions.

[0057] Example 2

[0058] A method for enhancing chlorine removal by using sulfite solution potential regulation and ultrasonic wave enhancement, the specific steps are as follows:

[0059] (1) Extract Cu 2+ :Cl - 1L of chlorine-containing pre-purification solution with a molar ratio of 1.4:1 was heated to 70°C;

[0060] (2) The sulfur dioxide gas is heated to 70° C. by a gas heating device, and is introduced into the chlorine-containing solution before purification at a flow rate of 0.5 L / min. The ultrasonic enhanced reaction is carried out for 50 min under the conditions of a temperature of 70° C., a stirring speed of 200 r / min, an ultrasonic power of 120 W, and an ultrasonic frequency of 30 kHz. The solid-liquid separation is performed to obtain a purified and dechlorinated liquid and a reaction precipitate residue; the reaction precipitate residue is vacuum dried at 70° C. to obtain a cuprous chloride precipitate residue.

[0061] (3) The content of the liquid component after purification and dechlorination is 0.57 g / L, and the chloride ion removal rate is 83.92%.

[0062] Example 3

[0063] A method for enhancing chlorine removal by using sulfite solution potential regulation and ultrasonic wave enhancement, the specific steps are as follows:

[0064] (1) Press SO3 2- :Cu 2+ :Cl -Dissolve 6.302 g of sodium sulfite in a molar ratio of 0.5:1.4:1 and heat to 60°C;

[0065] (2) Take 1L of chlorine-containing pre-purification solution and heat it to 60°C;

[0066] (3) A 0.05 mol / L sodium sulfite solution was slowly added to the chlorine-containing solution before purification at a uniform speed, and the ultrasonic enhanced reaction was carried out for 20 minutes at a temperature of 60°C, a stirring speed of 100 r / min, an ultrasonic power of 120 W, and an ultrasonic frequency of 30 kHz. The solid-liquid separation was performed to obtain a purified and chlorinated liquid and a reaction precipitate residue; the reaction precipitate residue was vacuum dried at 60°C to obtain a cuprous chloride precipitate residue.

[0067] (4) The content of the liquid component after purification and dechlorination is 0.17 g / L, and the chloride ion removal rate is 95.21%.

[0068] Example 4

[0069] A method for enhancing chlorine removal by using sulfite solution potential regulation and ultrasonic wave enhancement, the specific steps are as follows:

[0070] (1) Press SO3 2- :Cu 2+ :Cl - Dissolve 13.22 g of calcium sulfite in a molar ratio of 1.3:1.4:1 and heat to 50°C;

[0071] (2) Take 1L of chlorine-containing pre-purification solution and heat it to 50°C;

[0072] (3) A 0.13 mol / L calcium sulfite solution was slowly added to the chlorine-containing solution before purification at a uniform speed, and the ultrasonic enhanced reaction was carried out for 100 min at a temperature of 50°C, a stirring speed of 200 r / min, an ultrasonic power of 110 W, and an ultrasonic frequency of 30 kHz. The solid-liquid separation was performed to obtain a purified and dechlorinated liquid and a reaction precipitate residue; the reaction precipitate residue was vacuum dried at 65°C to obtain a cuprous chloride precipitate residue.

[0073] (4) The content of the liquid component after purification and dechlorination is 0.69 g / L, and the chloride ion removal rate is 80.54%.

[0074] Example 5

[0075] A method for enhancing chlorine removal by using sulfite solution potential regulation and ultrasonic wave enhancement, the specific steps are as follows:

[0076] (1) Press SO3 2- :Cu 2+ :Cl - Dissolve 11.35 g of sodium sulfite in a molar ratio of 0.9:1.4:1 and heat to 70°C;

[0077] (2) Take 1L of chlorine-containing pre-purification solution and heat it to 70°C;

[0078] (3) A 0.09 mol / L sodium sulfite solution was slowly added to the chlorine-containing solution before purification at a uniform speed, and the ultrasonic enhanced reaction was carried out for 50 minutes at a temperature of 70°C, a stirring speed of 200 r / min, an ultrasonic power of 120 W, and an ultrasonic frequency of 30 kHz. The solid-liquid separation was performed to obtain a purified and chlorinated liquid and a reaction precipitate residue; the reaction precipitate residue was vacuum dried at 70°C to obtain a cuprous chloride precipitate residue.

[0079] (4) The content of the liquid component after purification and dechlorination is 0.11 g / L, and the chloride ion removal rate is 96.90%.

[0080] Example 6

[0081] A method for enhancing chlorine removal by using sulfite solution potential regulation and ultrasonic wave enhancement, the specific steps are as follows:

[0082] (1) Press SO3 2- :Cu 2+ :Cl - Dissolve 11.61 g of ammonium sulfite in a molar ratio of 1:1.4:1 and heat to 70°C;

[0083] (2) Take 1L of chlorine-containing pre-purification solution and heat it to 70°C;

[0084] (3) A 0.1 mol / L ammonium sulfite solution was slowly added to the chlorine-containing solution before purification at a uniform speed, and the ultrasonic enhanced reaction was carried out for 50 minutes at a temperature of 70°C, a stirring speed of 200 r / min, an ultrasonic power of 120 W, and an ultrasonic frequency of 30 kHz. The solid-liquid separation was performed to obtain a purified and dechlorinated liquid and a reaction precipitate residue; the reaction precipitate residue was vacuum dried at 70°C to obtain a cuprous chloride precipitate residue.

[0085] (4) The content of the liquid component after purification and dechlorination is 0.21 g / L, and the chloride ion removal rate is 94.08%.

[0086] In summary, the present invention is adopted.

[0087] The above disclosure is only part of the embodiments of the present invention, which cannot be used to limit the scope of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention are still within the scope of the invention.

Claims

1. A method for regulating dissolved oxygen and potential dechlorination by using ultrasound in conjunction with a sulfite solution, characterized in that: The steps include: (1) dissolving sulfite in deionized water to obtain a sulfite solution; (2) heating the sulfite solution and the chlorine-containing solution to be treated respectively; (3) After the heating is completed, the sulfite solution is slowly and uniformly added to the chlorine-containing solution to be treated, and stirred for reaction, and ultrasonic waves are used to strengthen the reaction, and a purified liquid is obtained after the reaction is completed; (4) performing solid-liquid separation on the purified liquid to obtain a filtrate and a filter residue; and vacuum drying the filter residue.

2. The method of controlling dissolved oxygen and removing chlorine by using ultrasound and sulfite solution as claimed in claim 1, characterized in that: The concentration of the sulfite solution in step (1) is 0.05-0.2 mol / L.

3. The method of controlling dissolved oxygen and removing chlorine by using ultrasound and sulfite solution as claimed in claim 1, characterized in that: The sulfite in step (1) is one of sulfur dioxide fume, sodium sulfite, ammonium sulfite or calcium sulfite.

4. The method for controlling dissolved oxygen and removing chlorine by using ultrasound and sulfite solution as claimed in claim 1, characterized in that: The temperature in step (2) is raised to 50-100°C.

5. The method of controlling dissolved oxygen and removing chlorine by using ultrasound and sulfite solution as claimed in claim 1, characterized in that: When ultrasound is used to enhance the reaction in step (3), the ultrasound conditions are: frequency 20 to 50 kHz, power 10 to 120 W / L.

6. The method of controlling dissolved oxygen and removing chlorine by using ultrasound and sulfite solution as claimed in claim 1, characterized in that: During the stirring reaction in step (3), SO3 2- / Cl - The molar ratio is 0.5-2:1; Cu 2+ / Cl - The molar ratio is 1 to 2:1, and the reaction time is 20 to 100 minutes.

7. The method of controlling dissolved oxygen and removing chlorine by using ultrasound and sulfite solution as claimed in claim 1, characterized in that: The stirring rate in step (3) is 50 to 200 r / min.

8. The method of controlling dissolved oxygen and removing chlorine by using ultrasound and sulfite solution as claimed in claim 1, characterized in that: The drying temperature in step (4) is 60-75°C.

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