A modified electrolytic manganese anode mud for NH4 removal + Methods involving -N and heavy metals
By modifying electrolytic manganese anode mud to prepare catalysts, the problem of simultaneous removal of NH4+-N and heavy metals from wastewater was solved, achieving efficient and low-cost wastewater treatment and improving the activity and stability of the catalysts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHWEAT UNIV OF SCI & TECH
- Filing Date
- 2026-02-06
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies are difficult to efficiently and cost-effectively remove NH4+-N and heavy metals from wastewater simultaneously, and they also pose problems of secondary pollution and high operating costs.
Modified electrolytic manganese anode mud was used as a catalyst. Its catalytic activity was enhanced through modification treatment. It was then directly contacted with wastewater at room temperature and pressure to achieve simultaneous removal of NH4+-N and heavy metals.
It significantly improves the catalytic activity and stability of electrolytic manganese anode mud, reduces catalyst cost, and achieves efficient removal of NH4+-N and heavy metals without secondary pollution.
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Figure CN122144883A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wastewater treatment, specifically to a method for efficiently removing NH4 from wastewater using modified electrolytic manganese anode mud as a catalyst under normal temperature and pressure. + Methods involving -N and heavy metals. Background Technology
[0002] NH4 in water + The combined pollution of nitrogen (NH4) and heavy metals is a serious challenge currently facing the field of environmental governance. + Excessive nitrogen (NH4+) can lead to eutrophication and damage aquatic ecosystems. Furthermore, NH4+... + -N also poses a direct threat to human health, as it can be converted into nitrites in the body, which have carcinogenic and mutagenic risks. Heavy metals such as copper (Cu), iron (Fe), manganese (Mn), cobalt (Co), and nickel (Ni) are highly toxic, bioaccumulative, and non-degradable, seriously threatening human health and environmental safety. Current technologies often employ a process of "removing heavy metals first, then removing NH4." + The stepwise approach of "-N" has drawbacks such as high reagent consumption, secondary sludge pollution, high operating costs, and weak resistance to shock loads, making it difficult to meet the requirements of simultaneous, efficient, and low-consumption treatment. Researchers at GEM Co., Ltd. have developed a method for degrading NH4 in wastewater. + The -N method first removes heavy metals cobalt and nickel through a precipitation reaction, then adds an oxidant for a second precipitation reaction to remove manganese, achieving efficient removal of heavy metals. However, this method is complex and costly (CN202411496998.9). Therefore, it is necessary to develop a method that can simultaneously and efficiently remove NH4. + The integrated technology of -N and multiple heavy metals is crucial. In recent years, the concept of "treating waste with waste" has received much attention, and the preparation of water treatment catalysts from industrial solid waste has become an important way to realize its resource utilization. The large amount of anode mud generated during the electrolytic manganese process is a potential secondary resource, and its traditional disposal methods suffer from low efficiency and high environmental risks. Electrolytic manganese anode mud is a byproduct of the optimized electrolysis process. Its main component, manganese dioxide (MnO2), is a common active component and oxidant in environmental catalysis and has been extensively studied. However, due to its limited specific surface area, insufficient exposure of active sites, and poor pore structure, the original anode mud often performs poorly when directly used for catalytic oxidation. Activation modification can effectively regulate its surface physicochemical properties, increase active sites, and improve mass transfer conditions, thereby significantly improving catalytic performance. This strategy follows the principle of circular economy, using electrolytic manganese solid waste as raw material, which not only significantly reduces catalyst costs but also achieves high-value resource utilization of waste, combining environmental and economic benefits. The innovation of this invention lies in using modified electrolytic manganese anode mud as a catalyst, enabling the modified electrolytic manganese anode mud to possess catalytic oxidation capabilities, achieving NH4+ oxidation without the addition of any oxidant. + Efficient removal of -N and heavy metals. This method not only exhibits high catalytic activity but also demonstrates good environmental friendliness and economic efficiency. Compared with existing technologies, this invention has significant advantages in catalyst preparation, reaction mechanism, and application. Summary of the Invention
[0003] This invention discloses a method for removing NH4 from modified electrolytic manganese anode mud. + Methods involving -N and heavy metals to address NH4 in related technologies + Efficient methods for removing -N have technical problems such as high cost and secondary pollution. To solve the above problems, the present invention adopts the following technical solution: This invention relates to the method of removing NH4 from modified electrolytic manganese anode mud. + The method for dealing with -N and heavy metals includes the following steps: S100: Pre-treatment of electrolytic anode mud discharged from the electrolytic manganese workshop, including washing, drying, and crushing; S200: The electrolytic manganese anode mud obtained from S100 is thoroughly mixed with the modification solution according to the set ratio, and modified under the set temperature and time conditions; S300: The modified electrolytic manganese anode mud obtained from S200 is washed, filtered, and dried to obtain the modified electrolytic manganese anode mud sample. S400: Add modified anode mud containing NH4 at a certain ratio + Wastewater containing nitrogen and heavy metals is subjected to a thorough reaction and mixing under set reaction conditions. After the reaction is completed, solid-liquid separation is performed. The solids can be recycled after further modification, while the wastewater can be directly discharged after adjusting the pH value. According to an optional embodiment, in step S100, the liquid-to-solid ratio of the electrolytic manganese anode mud washing solution is 7:1 to 20:1, the drying temperature is 105°C, and the mesh size is 10 to 60 mesh. The liquid-to-solid ratio of the electrolytic manganese anode mud to the modifier solution is 5:1 to 20:1 mL / g. According to an optional embodiment, in step S200, the modified solution includes one or more of H2SO4, NaCl, Na2CO3, NaOH, and KOH, and the liquid-solid ratio of electrolytic manganese anode mud to the modified solution is 5:1 to 20:1 mL / g. According to an optional embodiment, in step S200, the concentration of the modifier solution is 0.5~5 mol / L, the modification reaction temperature is 25~90℃, and the modification reaction time is 0.5~12 h; According to an optional implementation, in step S300, the solid-to-water ratio of the modified electrolytic manganese anode mud washing solution is 10:1 to 100:1, and the drying temperature is 60°C. According to an optional implementation, in step S400, NH4 is included. + The initial pH value of wastewater containing nitrogen and heavy metals is 3~9; According to an optional implementation, in step S400, NH4 is included. + -N wastewater NH4 + -N concentration is 5~40 mg / L; According to an optional implementation, in step S400, the heavy metals in the heavy metal-containing wastewater include Fe. 2+ Cu 2 + Co 2+ Ni 2+ Mn 2+ One or more of them, with a concentration of 20~500 mg / L; According to an optional implementation, in step S400, the amount of modified electrolytic manganese anode mud is 1~30 g / L, the reaction temperature is 25~90℃, and the reaction time is 0.5~12 h; According to an optional implementation, in step S400, NH4 is removed. + The residue formed by -N and heavy metals is modified again by the solution obtained after modifying the electrolytic manganese anode mud in S200. According to an optional implementation, in step S400, the pH of the treated wastewater is adjusted to a range of 6-9. The technical solution adopted in this invention can achieve the following beneficial effects: This invention provides a method for preparing a catalyst by modifying the electrolytic manganese anode mud generated during the electrolytic manganese production process, and then using it for the removal of NH4.+ -N and heavy metal wastewater. This method first modifies electrolytic manganese anode sludge with a specific concentration of modification solution (preferably NaOH), followed by washing, filtration, and drying to obtain modified electrolytic manganese anode sludge. Under certain time and temperature conditions, the modified electrolytic manganese anode sludge can efficiently remove NH4 from wastewater. + -N and heavy metals. This invention significantly improves the catalytic activity and stability of electrolytic manganese anode mud through modification, solving the problems of high cost, narrow pH range and numerous by-products of traditional catalysts. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is an XRD pattern analysis of electrolytic manganese anode mud before and after modification with different modifiers. Detailed Implementation To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Example 1 In this embodiment, modified electrolytic manganese anode mud is used to remove NH4. + The -N and heavy metal methods include the following steps: A 2 mol / L NaOH solution was prepared. Under stirring, the electrolytic manganese anode mud was added to the NaOH solution at a liquid-to-solid ratio of 10:1. After reacting at 60℃ for 4 h, the mud was washed, filtered, and dried to obtain the modified electrolytic manganese anode mud. Preparation of 10 mg / L NH4 + -N solution, adjust NH4+ + The pH of the -N solution is 4. Under stirring, the modified electrolytic manganese anode mud is added to NH4+ at a concentration of 5 g / L. + In a -N solution, the mixture was reacted at 40°C for 2 h, followed by washing, filtration, and drying. The results showed that NH4 + -N removal rate can reach 92.35% (adsorption and catalytic oxidation account for 16.48% and 74.16%, respectively), NO3 --N concentration was 0.0349 mg / L, NO2 - -N concentration was 0.0454 mg / L, NH4 + The selective conversion rate of -N to N2 was 81.28%. Example 2 In this embodiment, modified electrolytic manganese anode mud is used to remove NH4. + The -N and heavy metal methods include the following steps: A 2 mol / L NaOH solution was prepared. Under stirring, the electrolytic manganese anode mud was added to the NaOH solution at a liquid-to-solid ratio of 10:1. After reacting at 80℃ for 4 h, the mud was washed, filtered, and dried to obtain the modified electrolytic manganese anode mud. Preparation of 10 mg / L NH4 + -N solution, without adjusting NH4+ + -N solution pH (5.74), under stirring, the modified electrolytic manganese anode mud was added to NH4+ at a concentration of 5 g / L. + In a -N solution, the mixture was reacted at 40°C for 2 h, followed by washing, filtration, and drying. The results showed that NH4 + -N removal rate can reach 98.13% (adsorption and catalytic oxidation account for 18.14% and 79.99%, respectively), NO3 - -N concentration was 0.0368 mg / L, NO2 - -N concentration was 0.0626 mg / L, NH4+ + The selective conversion rate of -N to N2 was 80.50%. Example 3 In this embodiment, modified electrolytic manganese anode mud is used to remove NH4. + The -N and heavy metal methods include the following steps: A 2 mol / L NaOH solution was prepared. Under stirring, the electrolytic manganese anode mud was added to the NaOH solution at a liquid-to-solid ratio of 10:1. After reacting at 60℃ for 4 h, the mud was washed, filtered, and dried to obtain the modified electrolytic manganese anode mud. Preparation of 10 mg / L NH4 + -N solution, adjust NH4+ + The pH of the -N solution was 7. The modified electrolytic manganese anode mud was added to NH4 under stirring, with a modified electrolytic manganese anode mud concentration of 5 g / L. + In a -N solution, the mixture was reacted at 40°C for 2 h, followed by washing, filtration, and drying. The results showed that NH4 +-N removal rate can reach 90.37% (adsorption and catalytic oxidation account for 17.91% and 72.46%, respectively), NO3 - -N concentration was 0.0123 mg / L, NO2 - -N concentration was 0.0330 mg / L, NH4 + The selective conversion rate of -N to N2 was 79.68%. Example 4 In this embodiment, modified electrolytic manganese anode mud is used to remove NH4. + The -N and heavy metal methods include the following steps: A 1.5 mol / L NaOH solution was prepared. Under stirring, the electrolytic manganese anode mud was added to the NaOH solution at a liquid-to-solid ratio of 10:1. After reacting at 60℃ for 4 h, the mixture was washed, filtered, and dried to obtain the modified electrolytic manganese anode mud. Preparation of 10 mg / L NH4 + -N solution, adjust NH4+ + The pH of the -N solution was 9. The modified electrolytic manganese anode mud was added to NH4 under stirring, with a modified concentration of 5 g / L. + In a -N solution, the mixture was reacted at 40°C for 2 h, followed by washing, filtration, and drying. The results showed that NH4 + -N removal rate can reach 86.98% (adsorption and catalytic oxidation account for 12.94% and 83.51%, respectively), NO3 - -N concentration was 0.0462 mg / L, NO2 - -N concentration was 0.0935 mg / L, NH4+ + The selective conversion rate of -N to N2 was 83.51%. Example 5 In this embodiment, modified electrolytic manganese anode mud is used to remove NH4. + The -N and heavy metal methods include the following steps: A 2 mol / L NaOH solution was prepared. Under stirring, the electrolytic manganese anode mud was added to the NaOH solution at a liquid-to-solid ratio of 10:1. After reacting at 60℃ for 4 h, the mud was washed, filtered, and dried to obtain the modified electrolytic manganese anode mud. Preparation of 10 mg / L NH4 + -N solution, without adjusting NH4+ + -N solution pH (5.74), under stirring, the modified electrolytic manganese anode mud was added to NH4+ at a concentration of 9 g / L. + In a -N solution, the mixture was reacted at 40°C for 2 h, followed by washing, filtration, and drying. The results showed that NH4 + -N removal rate can reach 96.19% (adsorption and catalytic oxidation account for 5.27% and 94.73%, respectively), NO3 - -N concentration was 0.0839 mg / L, NO2 - -N concentration is 0.0455 mg / L, NH4 + The selective conversion of -N to N2 was 94.90%, and after cycling it 10 times, NH4 + -N removal rate can still reach over 90%. Example 6 In this embodiment, modified electrolytic manganese anode mud is used to remove NH4. + The -N and heavy metal methods include the following steps: A 2 mol / L NaOH solution was prepared. Under stirring, the electrolytic manganese anode mud was added to the NaOH solution at a liquid-to-solid ratio of 10:1. After reacting at 60℃ for 4 h, the mud was washed, filtered, and dried to obtain the modified electrolytic manganese anode mud. Prepare 500 mg / L Co 2+ Ni 2+ The mixed solution was not adjusted to pH (3.04). Modified electrolytic manganese anode mud was added to the above mixed solution with stirring at a concentration of 5 g / L. After reacting at 40℃ for 2 h, the mixture was washed, filtered, and dried. The results showed that the removal amounts of Co and Ni could reach 351.30 and 354.20 mg / g, respectively. Example 7 In this embodiment, modified electrolytic manganese anode mud is used to remove NH4. + The -N and heavy metal methods include the following steps: A 1.5 mol / L NaOH solution was prepared. Under stirring, the electrolytic manganese anode mud was added to the NaOH solution at a liquid-to-solid ratio of 10:1. After reacting at 60℃ for 4 h, the mixture was washed, filtered, and dried to obtain the modified electrolytic manganese anode mud. Prepare 250 mg / L Co 2+ Ni 2+ Fe 2+ Cu 2+ Mn 2+ The mixed solution was prepared without pH adjustment. Modified electrolytic manganese anode mud was added to the above mixed solution with stirring at a concentration of 9 g / L. After reacting at 40℃ for 2 h, the mixture was washed, filtered, and dried. The results showed that Co 2+ Ni2+ Fe 2+ Cu 2+ and Mn 2+ The removal rates can reach 70.81%, 65.05%, 99.99%, 99.98% and 89.63%, respectively. Comparative Example 1 This comparative example demonstrates the removal of NH4 from modified electrolytic manganese anode mud. + The -N and heavy metal methods include the following steps: Preparation of 10 mg / L NH4 + -N solution, adjust NH4+ + The -N solution has a pH of 9. The modified manganese anode mud was added to NH4 under stirring, with a concentration of 5 g / L. + In a -N solution, the mixture was reacted at 40°C for 2 h, followed by washing, filtration, and drying. The results showed that NH4 + -N removal rate was -7.25% (because electrolytic manganese anode mud contains NH4). + -N), without any adsorption or catalytic oxidation of NH4. + -N effect. Comparative Example 2 This comparative example demonstrates the removal of NH4 from modified electrolytic manganese anode mud. + The -N and heavy metal methods include the following steps: Preparation of 10 mg / L NH4 + -N solution, adjust NH4+ + The -N solution has a pH of 9. After stirring at 40°C for 2 hours, the mixture is filtered. Comparative Example 3 Prepare 250 mg / L Co 2+ Ni 2+ Fe 2+ Cu 2+ Mn 2+ The mixed solution was prepared without pH adjustment. Electrolytic manganese anode mud was added to the mixed solution with a concentration of 9 g / L under stirring. After reacting at 40℃ for 2 h, the mixture was washed, filtered, and dried. The results showed that Co 2+ Ni 2+ Fe 2+ Cu 2+ and Mn 2+ The removal rates can reach 29.47%, 27.81%, 29.99%, 19.76% and -15.39% respectively (because the anode mud itself contains soluble manganese). It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples. The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A modified electrolytic manganese anode mud for removing NH4 + The method for -N and heavy metals, characterized in that... Includes the following steps: S100: Pre-treatment of electrolytic anode mud discharged from the electrolytic manganese workshop, including washing, drying, and crushing; S200: The electrolytic manganese anode mud obtained from S100 is thoroughly mixed with the modification solution according to the set ratio, and modified under the set temperature and time conditions; S300: The modified electrolytic manganese anode mud obtained from S200 is washed, filtered, and dried to obtain the modified electrolytic manganese anode mud sample. S400: Add modified anode mud containing NH4 at a certain ratio + Wastewater containing nitrogen and heavy metals is subjected to a thorough reaction and mixing under set reaction conditions. After the reaction is completed, solid-liquid separation is performed. The solids can be recycled after further modification, while the wastewater is discharged directly after adjusting the pH value.
2. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S100, the electrolytic manganese anode mud is washed with water at a ratio of 7:1 to 20:1 mL / g, and then dried and crushed to 10 to 60 mesh at 105°C.
3. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S200, the modified solution includes one or more of H2SO4, NaCl, Na2CO3, NaOH, and KOH. Electrolytic manganese anode mud is mixed with 0.5~5 mol / L modified solution at a liquid-solid ratio of 5:1~20:1 mL / g at 25~90℃ for 0.5~12h.
4. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S300, the modified electrolytic manganese anode mud is washed with water and then dried at 60°C according to a liquid-solid ratio of 10:1 to 100:
1.
5. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S400, the initial pH value of the wastewater is 3 to 9.
6. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S400, NH4 + -N concentration is 5~40 mg / L.
7. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S400, the heavy metals include Fe. 2+ Cu 2+ Co 2+ Ni 2+ Mn 2+ One or more of them, with a concentration of 20~500 mg / L.
8. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S400, the modified electrolytic manganese anode mud is reacted with wastewater at a dosage of 1~30 g / L for 0.5~12 h at 25~90℃.
9. The method for removing NH4 from modified electrolytic manganese anode mud according to claim 1 + The method for -N and heavy metals, characterized in that... In step S400, NH4 is removed. + The residue formed by -N and heavy metals is further modified by a solution obtained after modifying electrolytic manganese anode mud in S200.
10. A modified electrolytic manganese anode mud for removing NH4 according to claim 1 + The method for -N and heavy metals, characterized in that... In step S400, the pH of the wastewater is adjusted to 6-9 before being discharged.