Method for removing manganese by chlorine oxidation catalyzed by enhanced carbon-based materials

Abstract

This disclosure provides a method for removing manganese by chlorine oxidation catalyzed by a reinforced carbon-based material, belonging to the field of water treatment technology. The method comprises adding the reinforced carbon-based material to a manganese-containing water body and mixing the mixture to obtain a reaction solution; adding chlorine to the reaction solution and adjusting the pH, and then catalyzing the chlorine oxidation reaction using the reinforced carbon-based material to remove manganese; wherein the reinforced carbon-based material is activated carbon that has undergone a reinforced treatment, and the reinforced treatment includes at least one of ultrasonic treatment and steam secondary activation.

Description

Technical Field

[0001] The present disclosure belongs to the field of water treatment technology, and in particular relates to a method for removing manganese by chlorine oxidation catalyzed by enhanced carbon-based materials. Background Art

[0002] Mn(II) is a vital element in the natural cycle and is ubiquitously distributed in a variety of natural water environments, including rivers, lakes, and artificial reservoirs. Its concentration in water bodies exhibits a significant range, with routine detection values ​​ranging from trace levels (μg / L) to hundreds of times the concentration (mg / L). In the field of drinking water purification, when Mn(II)-containing water enters the water treatment system, its retention efficiency is generally limited. Unremoved Mn(II) components undergo redox reactions during transport, forming dense deposits that adhere to the inner surface of the pipe walls. Changing hydraulic conditions can easily lead to abnormal turbidity, manifesting as a rusty or blackish color change in the water at the end of the pipe network. Furthermore, in industrial water bodies, Mn(II)-containing water discharged from industries such as metallurgy and electroplating often exceeds environmental emission standards by several orders of magnitude. Existing activated carbon adsorption processes are very ineffective in removing Mn(II). Summary of the Invention

[0003] In response to the above technical problems, the present disclosure provides a method for removing manganese by chlorine oxidation using an enhanced carbon-based material catalyzed by carbon-based materials, in order to at least partially solve the above technical problems. The technical solution of the present disclosure is as follows.

[0004] According to an embodiment of the present disclosure, a method for removing manganese by catalyzing chlorine oxidation using a reinforced carbon-based material is provided, comprising: adding the reinforced carbon-based material into a manganese-containing water body and mixing the mixture to obtain a reaction liquid; adding chlorine to the reaction liquid and adjusting the pH, and utilizing the reinforced carbon-based material to catalyze a chlorine oxidation reaction to remove manganese; wherein the reinforced carbon-based material is activated carbon that has undergone a reinforced treatment, and the reinforced treatment comprises at least one of ultrasonic treatment and secondary activation with water vapor.

[0005] In the embodiments of the present disclosure, the carbon-based material is subjected to ultrasonic treatment, and the cavitation effect generated by ultrasound is used to increase the pores and surface active sites of the carbon-based material, so as to achieve the purpose of strengthening the carbon-based material to improve the catalytic activity. Alternatively, by subjecting the activated carbon to a secondary water vapor activation treatment, water vapor is used to increase the richness of the pores in the carbon-based material and simultaneously achieve the reorganization of the surface functional groups, which can also achieve the purpose of strengthening the carbon-based material to improve the catalytic activity. Subsequently, the strengthened and modified carbon-based material is used as a catalyst in combination with chlorine to catalytically oxidize manganese-containing water bodies, which can achieve efficient removal of manganese. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 Schematic diagram of the principle of enhanced carbon-based material catalyzing chlorine oxidation to remove manganese in an embodiment of the present disclosure;

[0007] Figure 2This is a diagram showing the effect of removing manganese from water in Comparative Examples 1 and 2 of the present disclosure;

[0008] Figure 3 This is a diagram showing the effect of ultrasonic enhanced treatment of activated carbon to remove manganese from water in Examples 1 to 6 of the present disclosure;

[0009] Figure 4 This is a diagram showing the effect of removing manganese from water by secondary activation of activated carbon with steam in Examples 1, 7, and 9 of the present disclosure;

[0010] Figure 5 This is a diagram showing the effect of different activated carbons in removing manganese from water in Examples 10 to 12 of the present disclosure;

[0011] Figure 6 These are morphological pictures of different activated carbons in the embodiments of the present disclosure, wherein (a) is untreated coal-based powdered activated carbon, (b) is coal-based powdered activated carbon ultrasonically treated for 30 min, (c) is coal-based powdered activated carbon secondary activated by steam, (d) is untreated straw-based powdered activated carbon, (e) is straw-based powdered activated carbon ultrasonically treated for 30 min, and (f) is straw-based powdered activated carbon secondary activated by steam. DETAILED DESCRIPTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0013] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The term "comprising" used herein indicates the presence of features, steps, operations, but does not exclude the presence or addition of one or more other features.

[0014] During the implementation of the present invention, it was discovered that the effectiveness of manganese removal using methods such as chlorine oxidation or activated carbon adsorption alone is very limited. Improving the efficiency of activated carbon in removing manganese (Mn(II)) from water bodies is an urgent problem that needs to be solved. Furthermore, carbon-based materials (such as activated carbon) of different materials exhibit significant differences in their efficiency in catalyzing chlorine oxidation to remove Mn(II). For example, coal-based activated carbon is less catalytic than coconut shell-based activated carbon, and the two pale in comparison in their ability to catalyze chlorine oxidation to remove Mn(II). Therefore, a universal method is needed to treat carbon-based materials of different materials to significantly enhance their Mn(II) removal capabilities. To this end, the present invention proposes using an economical and effective enhanced modification technology to treat carbon-based materials, significantly enhancing their catalytic Mn(II) removal capabilities. This method is universally applicable to carbon-based materials of different materials, and the method provided by the present invention has important practical application value for water quality safety and environmental protection.

[0015] Specifically, according to an embodiment of the present disclosure, a method for removing manganese by catalytic chlorine oxidation using a reinforced carbon-based material is provided, comprising: adding the reinforced carbon-based material into a manganese-containing water body and mixing the mixture to obtain a reaction liquid; adding chlorine to the reaction liquid and adjusting the pH, and using the reinforced carbon-based material to catalyze the chlorine oxidation reaction to remove manganese; wherein the reinforced carbon-based material is activated carbon that has undergone reinforced treatment, and the reinforced treatment includes at least one of ultrasonic treatment and secondary activation with water vapor.

[0016] Figure 1 Schematic diagram of the principle of enhanced carbon-based material catalyzed chlorine oxidation to remove manganese in an embodiment of the present disclosure.

[0017] In the embodiments of the present disclosure, Figure 1 As shown, ultrasonic modification of carbon-based materials utilizes the cavitation effect generated by ultrasound to increase the porosity and surface active sites of the carbon-based materials, thereby strengthening the carbon-based materials and improving their catalytic activity. Alternatively, secondary activation of activated carbon with steam can be achieved by using steam to increase the type and number of pores in the carbon-based materials (increasing pore richness) while simultaneously reorganizing surface functional groups, thereby strengthening the carbon-based materials and improving their catalytic activity. Subsequently, the modified carbon-based materials are used as catalysts in combination with chlorine, where they catalyze the oxidation of manganese-containing water with available chlorine, achieving efficient manganese removal.

[0018] According to embodiments of the present disclosure, when the strengthening treatment is ultrasonic treatment, obtaining the strengthened carbon-based material includes: ultrasonically treating a suspension of activated carbon and water; or performing the ultrasonic treatment during a catalytic chlorination reaction to remove manganese (Mn(II)). Whether ultrasonically modifying the activated carbon first or performing the ultrasonic treatment during the catalytic reaction, ultrasound can simultaneously expand the pores of the strengthened carbon-based material and increase contact between the material and the manganese-containing water, and both methods significantly improve the Mn(II) removal effect.

[0019] According to an embodiment of the present disclosure, the power of ultrasonic treatment is 10-20000W, preferably 150-2000W, the frequency is 20-200kHz, preferably 20-100kHz, and the time is 1min-100min, preferably 1min-60min, and more preferably the power of ultrasonic treatment is 2000W, the frequency is 40kHz, and the time is 30min-60min.

[0020] In the embodiments disclosed herein, ultrasound in the range of 10-20,000W or 150-2,000W can generate a sufficient cavitation effect, causing a large number of tiny bubbles to form in the suspension or reaction solution. These bubbles rapidly grow and collapse, creating a localized environment of elevated temperature and pressure. This environment can be exploited to subject the activated carbon (carbon-based material) surface to intense mechanical impact and chemical modification, improving its surface pore structure and enhancing its catalytic activity. Furthermore, the ultrasound treatment frequency is set between 20-200kHz, preferably 20-100kHz, encompassing the advantages of both low frequencies (20kHz) and high frequencies (100kHz or higher, 200kHz). Low-frequency ultrasound has a stronger cavitation ability, generating larger cavitation bubbles and greater mechanical impact, helping to activate surface pores and achieve deep modification. High-frequency or higher-frequency ultrasound, on the other hand, has greater penetration and directionality, enabling a more uniform effect on the activated carbon, resulting in a more uniform and consistent modification effect. When operated at a power of 20,000W or 2,000W, the activated carbon can achieve a significant modification effect in a shorter period of time, thereby exhibiting better removal performance in the synergistic chlorine oxidation to remove Mn(II), thereby improving the removal efficiency and treatment effect of manganese.

[0021] According to an embodiment of the present disclosure, when the strengthening treatment is secondary activation with water vapor, obtaining the strengthened carbon-based material includes placing the activated carbon in an inert reactor and introducing water vapor to activate it at 500-1200°C for 0.5-1.5 hours. The reactor can be a tubular furnace, and the activation is preferably performed at 800-900°C, with a water vapor flow rate of 1-100 mL / min.

[0022] In the embodiments of the present disclosure, during the secondary activation process of high-temperature steam, the steam reacts with impurities or residues in the activated carbon, and the generated gas or soluble substances are removed, forming new pores (such as increased micropores and / or mesopores) inside the activated carbon, making the pore structure more developed, significantly increasing the specific surface area of ​​the activated carbon, and thus improving the catalytic performance of the activated carbon material. In addition, the ultrasonic treatment and steam secondary activation treatment of the present disclosure can be used independently or in combination, and the enhanced manganese removal method provided by the present disclosure is applicable to activated carbon of different water qualities and different materials. Compared with activated carbon that has not been subjected to enhanced modification treatment, the removal efficiency of Mn(II) can be increased by more than 50% when the enhanced carbon-based material (i.e., modified activated carbon material) is combined with chlorine to catalyze chlorine oxidation to remove Mn(II).

[0023] According to the embodiments of the present disclosure, the water body includes: natural water bodies, tap water, industrial waste water, etc. The specific source of the water body is not limited here, and any water source can be used. The activated carbon is derived from at least one of wood (such as coconut shell, fruit shell, wood), coal (such as anthracite, bituminous coal), petroleum coke, peat, bone charcoal (such as animal bone charcoal), synthetic carbon-based materials (such as resin-based, carbon fiber), bamboo charcoal, and crops (such as rice husks, straw). Other carbon-based solid waste powders can also be used, which will not be described in detail here. Before use, screening with a sieve to obtain activated carbon with uniform particle size can be beneficial to obtaining a higher Mn(II) removal effect. Generally, a 100-200 mesh sieve can meet the requirements. After screening, the activated carbon powder is washed with deionized water to remove surface impurities, and then stored for use after drying.

[0024] According to an embodiment of the present disclosure, the reinforcing carbon-based material and the manganese-containing water may be mixed by mechanical stirring or natural mixing by water flow, or may be mixed by ultrasonic mixing.

[0025] According to an embodiment of the present disclosure, the added chlorine is sodium hypochlorite or liquid chlorine, and the concentration of the added chlorine varies with the concentration of manganese in the water body.

[0026] According to an embodiment of the present disclosure, after adding chlorine to the reaction solution composed of the reinforced carbon-based material and the manganese water, the pH is adjusted to 5.5-10.0. The pH adjustment can be achieved by adding an acid or a base, wherein the acid can be selected from at least one of chloric acid, sulfuric acid, and nitric acid, and the base can be selected from at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, and sodium carbonate. Other bases or acids can be used and are not further limited herein. Furthermore, the pH is preferably adjusted to 6.5-9.0.

[0027] According to the embodiments of the present disclosure, the manganese concentration is 0.05-1000 mg / L, the content of available chlorine in the added chlorine is 0.1-2000 mg / L, and the concentration of the carbon-based material is 1-5000 mg / L. The concentrations of the added carbon-based material and chlorine vary with the change in the manganese concentration in the water. For example, when the manganese concentration is 0.05-100 mg / L, the content of available chlorine in the added chlorine is 0.5-10 mg / L, and the concentration of the carbon-based material is 5-100 mg / L. Generally, a concentration of 20 mg / L of carbon-based material can meet the requirements for rapid and efficient removal of Mn(II) from water; a concentration of 1-10 mg / L of available chlorine in water can meet the requirements for catalytic chlorine oxidation to remove Mn(II).

[0028] According to an embodiment of the present disclosure, the temperature of the catalytic chlorine oxidation reaction is 0-35°C, which is close to the temperature of water in an actual environment, and the reaction time is 10-120 minutes. The preferred temperature of the catalytic chlorine oxidation reaction is 5-35°C, more preferably 10-35°C, and the reaction time is 10-60 minutes. After the catalytic chlorine oxidation reaction is completed, a solid-liquid separation process is performed to monitor the manganese removal effect of the water body, wherein the solid-liquid separation method can be any one of gravity sedimentation separation, filtration separation, and centrifugal separation. In practical applications, gravity sedimentation separation can be used.

[0029] The method for removing manganese by chlorine oxidation catalyzed by the enhanced carbon-based material provided by the present disclosure is described in detail below with reference to specific examples and drawings.

[0030] Comparative Example

[0031] Comparative Example 1

[0032] 1L of water containing 0.4mg / L Mn(II) (25℃, pH=7.8) was added with sodium hypochlorite (available chlorine 2.0mg / L) and mixed evenly (mechanical stirring). After reacting for 120min, the water was filtered through a membrane and the residual Mn(II) concentration in the water was determined by inductively coupled plasma mass spectrometry (ICP-MS). The specific test results are shown in Table 1 and Figure 2 shown.

[0033] Comparative Example 2

[0034] 1L of water containing 0.4mg / L Mn(II) (25℃, pH=7.8) was added with 10mg / L untreated coal-based powdered activated carbon, mixed evenly, and reacted for 120min before filtration. The residual Mn(II) concentration in the water was determined by inductively coupled plasma mass spectrometry (ICP-MS). The specific test results are shown in Table 1 and Figure 2 shown.

[0035] Figure 2This is a diagram showing the effect of removing manganese from water in Comparative Examples 1 and 2 of the present disclosure.

[0036] like Figure 2 As shown in the results, neither chlorine alone nor activated carbon alone can effectively remove Mn(II) from water, and the adsorption performance of activated carbon is very limited.

[0037] Example 1

[0038] Example 1: Manganese was removed from water using the same method as Comparative Example 1, except that 10 mg / L of untreated coal-based powdered activated carbon and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed well, and subjected to a catalytic oxidation reaction for 60 min. After the reaction, the residual Mn(II) concentration in the water was measured using ICP-MS. The specific test results are shown in Tables 1 and Figure 3 shown.

[0039] Example 2

[0040] Example 2 used the same method as Comparative Example 2 to remove manganese from water, except that: 1 L of water containing 0.4 mg / L Mn(II) was added with only 10 mg / L of coal-based powdered activated carbon that had been ultrasonically treated for 30 minutes, mixed evenly, and allowed to adsorb for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured using ICP-MS. The specific test results are shown in Tables 1 and Figure 3 shown.

[0041] Example 3

[0042] Example 3 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of coal-based powdered activated carbon that had been ultrasonically treated for 1 minute and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 3 shown.

[0043] Example 4

[0044] Example 4 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of coal-based powdered activated carbon that had been ultrasonically treated for 10 minutes and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 3 shown.

[0045] Example 5

[0046] Example 5 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of coal-based powdered activated carbon that had been ultrasonically treated for 30 minutes and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 3 shown.

[0047] Example 6

[0048] Example 6 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of coal-based powdered activated carbon that had been ultrasonically treated for 60 minutes and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 3 shown.

[0049] Figure 3 This is a diagram showing the effect of removing manganese from water by ultrasonic enhanced treatment of activated carbon in Examples 1 to 6 of the present disclosure.

[0050] like Figure 3As shown, when untreated coal-based powdered activated carbon is used in conjunction with available chlorine (as in Example 1), the removal rate reaches 44.5% after 10 minutes and 82.5% after 30 minutes. When coal-based powdered activated carbon treated with ultrasonic treatment for 1 minute and available chlorine is used for Mn(II) removal from water (as in Example 3), the Mn(II) removal efficiency is improved, reaching 90% after 30 minutes. This demonstrates that ultrasonic treatment of activated carbon in conjunction with chlorine catalytic oxidation enhances Mn(II) removal. Increasing the ultrasonic treatment time from 1 minute to 60 minutes increases the Mn(II) removal rate within 10 minutes from 53.5% to 67%. Compared to the untreated coal-based powdered activated carbon in Example 1, extending the ultrasonic treatment time further strengthens the activated carbon, improving the pore structure and richness of the activated carbon surface, and enhancing Mn(II) removal efficiency. Among them, when the coal-based powdered activated carbon was ultrasonically treated for 30 minutes, the removal rate of Mn(II) reached 97.1% within 30 minutes, and the removal rate of Mn(II) reached 97.4% within 60 minutes. Therefore, activated carbon ultrasonically treated for 30 minutes can be used in practical applications. In addition, as shown in Comparative Examples 1-2 and Examples 1-6, coal-based powdered activated carbon without enhanced treatment, coal-based powdered activated carbon with enhanced treatment alone, or chlorination alone cannot effectively improve the removal rate of Mn(II).

[0051] Example 7

[0052] Example 7 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of coal-based powdered activated carbon that had been secondary activated at a steam flow rate of 0 mL / min and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 4 shown.

[0053] Example 8

[0054] Example 8 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of coal-based powdered activated carbon that had been secondary activated at a steam flow rate of 1.5 mL / min and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to a catalytic oxidation reaction for 60 minutes. After the reaction was completed, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 4 shown.

[0055] Example 9

[0056] Example 9 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of coal-based powdered activated carbon that had been secondary activated at a steam flow rate of 3 mL / min and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to a catalytic oxidation reaction for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 4 shown.

[0057] Figure 4 This is a diagram showing the effect of removing manganese from water by secondary activation treatment of activated carbon with water vapor in Examples 1, 7, and 9 of the present disclosure.

[0058] like Figure 4 As shown in the results, compared with the untreated coal-based powdered activated carbon, the coal-based powdered activated carbon was subjected to secondary steam activation. When the modified coal-based powdered activated carbon was used in conjunction with chlorine, the removal efficiency of Mn(II) in water was effectively improved.

[0059] Example 10

[0060] Example 10 used the same method as Comparative Example 1 to remove manganese from water, except that 10 mg / L of untreated straw-based powdered activated carbon and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 5 shown.

[0061] Example 11

[0062] Example 11 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of straw-based powdered activated carbon that had been ultrasonically treated for 30 minutes and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 minutes. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 5 shown.

[0063] Example 12

[0064] Example 12 used the same method as Comparative Example 1 to remove manganese from water, except that: 10 mg / L of straw-based powdered activated carbon, which had been secondary activated with a steam flow rate of 3 mL / min, and 2.0 mg / L of available chlorine were added to 1 L of water containing 0.4 mg / L of Mn(II), mixed evenly, and subjected to catalytic oxidation for 60 min. After the reaction, the residual Mn(II) concentration in the water was measured by ICP-MS. The specific test results are shown in Tables 1 and Figure 5 shown.

[0065] Figure 5 This is a diagram showing the effect of different activated carbons in removing manganese from water in Examples 10 to 12 of the present disclosure.

[0066] like Figure 5 As shown, compared with untreated straw-based powdered activated carbon, enhanced modification of straw-based powdered activated carbon using ultrasound and chlorine-catalyzed oxidation achieved faster and more effective Mn(II) removal from water, compared to untreated straw-based powdered activated carbon, within the same Mn(II) removal time. Secondary steam activation of straw-based powdered activated carbon, combined with chlorine-catalyzed oxidation, achieved a Mn(II) removal rate of 95% within 10 minutes and 99.9% within 30 minutes, achieving even more complete removal. Differences in enhanced modification between coal-based and straw-based powdered activated carbon using steam secondary activation may be due to differences in pore density between the two. For the looser straw-based powdered activated carbon, steam secondary activation allows for more complete pore expansion.

[0067] Table 1

[0068]

[0069] Furthermore, the specific surface areas of some activated carbons in Comparative Examples 1-2 and Examples 1-11 were measured, and the specific measurement results are shown in Table 2.

[0070] Table 2

[0071]

[0072] Table 2 shows that both ultrasonic treatment and steam secondary activation can improve the specific surface area of ​​coal-based powdered activated carbon, with comparable effects. For straw-based powdered activated carbon, steam secondary activation doubles the specific surface area and significantly exceeds that of ultrasonically modified activated carbon. Therefore, steam secondary activation is preferred for modified straw-based powdered activated carbon.

[0073] Furthermore, in combination with Table 1 and Table 2, the specific surface area of ​​the carbon-based material after the enhanced modification has increased to varying degrees, and the efficiency of the enhanced carbon-based material in catalytically removing Mn(II) has also been improved, and both can efficiently remove Mn(II), indicating that there is a certain correlation between the specific surface area of ​​the enhanced carbon-based material and the efficiency of catalytic chlorine oxidation to remove Mn(II). Compared with traditional unmodified powdered activated carbon, the method provided by the present invention has an Mn(II) removal rate improvement of at least 50%, and a significant improvement in the efficiency of removing Mn(II). At the same time, the required processing time is shorter, and the required amount of powdered activated carbon added is also less. In addition, the powdered activated carbon enhanced modification method disclosed in the present invention is not only simple to operate, but also does not require chemical reagents, making it a highly efficient and economical enhanced method for removing Mn(II).

[0074] Figure 6 These are morphological pictures of different activated carbons in the embodiments of the present disclosure, wherein (a) is untreated coal-based powdered activated carbon, (b) is coal-based powdered activated carbon ultrasonically treated for 30 min, (c) is coal-based powdered activated carbon secondary activated by steam, (d) is untreated straw-based powdered activated carbon, (e) is straw-based powdered activated carbon ultrasonically treated for 30 min, and (f) is straw-based powdered activated carbon secondary activated by steam.

[0075] like Figure 6 As shown in the figure, according to the characterization results, compared with untreated coal-based powdered activated carbon and straw-based powdered activated carbon, the specific surface area and surface pore richness of activated carbon after ultrasonic treatment or water vapor secondary activation treatment are significantly increased.

[0076] In summary, the method for strengthening and modifying carbon-based materials provided herein does not require complicated chemical modification treatment, has a short modification time, is relatively simple to operate, and has a significant effect in removing Mn(II).

[0077] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for removing manganese by chlorine oxidation catalyzed by a reinforced carbon-based material, comprising: adding the reinforced carbon-based material into a manganese-containing water body and mixing the mixture to obtain a reaction liquid; adding chlorine to the reaction solution and adjusting the pH, and using the reinforced carbon-based material to catalyze a chlorine oxidation reaction to remove manganese; Wherein, the reinforced carbon-based material is activated carbon after reinforcement treatment, and the reinforcement treatment includes at least one of ultrasonic treatment and steam secondary activation; Wherein, when the strengthening treatment is secondary activation with water vapor, obtaining the strengthened carbon-based material comprises: Place the activated carbon in an inert reactor, introduce water vapor and activate it at 500-1200°C for 0.5-1.5h.

2. The method according to claim 1, wherein In the case where the strengthening treatment is ultrasonic treatment, obtaining the strengthened carbon-based material comprises: Ultrasonic treatment of a suspension of activated carbon and water; or Ultrasonic treatment is carried out during the catalytic chlorine oxidation reaction for manganese removal.

3. The method according to claim 2, wherein: The ultrasonic treatment has a power of 10-20000W, a frequency of 20-200kHz, and a time of 1 min-100 min.

4. The method according to any one of claims 1 to 3, wherein The activated carbon is derived from at least one of wood, coal, petroleum coke, peat, bone char, synthetic carbon-based materials, bamboo charcoal, and crops.

5. The method according to claim 1, wherein The added chlorine is sodium hypochlorite or liquid chlorine.

6. The method according to claim 5, wherein: Adjusting the pH to 5.5-10.0; Wherein, the pH is adjusted by adding acid or base.

7. The method according to claim 1, wherein The concentration of manganese is 0.05-1000 mg / L, the content of effective chlorine in the added chlorine is 0.1-2000 mg / L, and the concentration of the carbon-based material is 1-5000 mg / L.

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