A carbon material stepwise self-catalytic oxidation regeneration method based on oxidant coupling addition
Patent Information
- Application Number
- CN202611336310.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-31
- Publication Date
- 2026-11-03
AI Technical Summary
Existing carbon material regeneration technologies suffer from poor economic efficiency, high energy consumption due to high-temperature pyrolysis, and poor regeneration effects of conventional oxidants, making it difficult to efficiently treat complex pollutants.
A stepwise autocatalytic oxidation regeneration method using coupled oxidant addition is employed. Based on the oxidizing power of the oxidants, oxidants such as persulfate, perdisulfate, ozone, hydrogen peroxide, or hypochlorite are added in one or several batches to achieve in-situ or ex-situ regeneration of carbon materials.
It improves the regeneration efficiency of carbon materials, reduces energy consumption and costs, is applicable to the efficient oxidative degradation of various pollutants, is easy to implement and does not change existing structures, and is economical and feasible.
Smart Images
Figure SMS_1 
Figure SMS_2 
Figure SMS_3
Abstract
Description
Technical Field
[0001] This invention belongs to the field of carbon material regeneration and application technology, and relates to a stepwise autocatalytic oxidation regeneration method for carbon materials based on the coupled addition of oxidant. Background Technology
[0002] The abundant sources of raw materials for carbon material preparation and the mature manufacturing processes have resulted in a wide variety of commercially available carbon materials, which are continuously used in environmental protection, energy storage, and chemical industries. Currently, carbon materials that have been commercialized or received widespread attention in the environmental protection field mainly include activated carbon, activated coke (a low-cost coal-based activated carbon), activated carbon fibers, graphite, diamond, biochar, carbon nanotubes, and graphene. Among these, activated carbon and activated coke have long been used in environmental protection fields such as water treatment and air pollution control. For example, the activated coke loading in the tertiary adsorption unit for the deep purification of secondary effluent in a wastewater treatment plant reaches tens of thousands of tons. Saturated activated coke is hazardous waste, and its recycling value is immeasurable.
[0003] Currently, the most widely used carbon material regeneration technology remains high-temperature pyrolysis, which requires transferring saturated or unusable carbon materials to a regeneration furnace for ex-situ regeneration. However, pyrolysis regeneration relies on expensive equipment such as regeneration furnaces, necessitates continuous transfer of the regenerated carbon materials, and results in significant energy consumption due to the high temperatures. Therefore, from a practical engineering application perspective, there is an urgent need for in-situ carbon material regeneration technologies that combine technical and economic viability with engineering practicality to further reduce the cost of using carbon materials and enhance their competitiveness in practical applications.
[0004] Activated carbon and activated coke exhibit strong adaptability to water quality in water treatment, effectively treating industrial wastewater, municipal sewage, and slightly polluted raw water. The types of pollutants involved are diverse, including various emerging pollutants such as pharmaceuticals and personal care products, endocrine disruptors, persistent organic pollutants, and artificial sweeteners, as well as natural organic matter such as humic acid and microbial metabolites. These pollutants possess varying charge properties, aromaticity, and ionization characteristics, often exhibiting more persistent co-adsorption on activated carbon and activated coke, making satisfactory regeneration difficult to achieve with conventional acid, alkali, or organic solvent regeneration methods alone.
[0005] Advanced oxidation processes (AOPs) are recognized as highly efficient technologies for treating pollutants in water. AOPs processes generate large amounts of hydroxyl radicals (-OH) and persulfate radicals (SO4). - Singlet oxygen ( 1 O2) and superoxide radical negative ions (O2) -Strong oxidizing species such as persulfate (PMS) can completely oxidize organic pollutants into carbon dioxide and water. AOPs have advantages such as rapid reaction, high oxidation rate constant, wide applicability, and ease of automation. A commonly used commercial oxidant in water treatment AOPs processes is persulfate (PMS) (E... Φ =1.82 V), persulfate (PDS) (E Φ =2.01 V), ozone (E Φ =2.07 V), hydrogen peroxide (E Φ =1.76 V) and hypochlorite (E Φ Oxidants such as (e.g., 0.84 V) have found different applications in water treatment due to their varying reactivity, economic efficiency, and practicality. These oxidants can oxidize the organic matter adsorbed on the surface of carbon materials, thus regenerating the carbon materials. At the same time, these oxidants can also catalytically oxidize the surface of adsorbed saturated carbon materials, producing a series of strongly oxidizing species (the amount, type, and contribution rate of which vary depending on the oxidant used), thereby more efficiently degrading the organic matter adsorbed on the surface of the carbon materials and achieving the regeneration of adsorbed saturated carbon materials.
[0006] In recent years, researchers have shifted their focus to in-situ or ex-situ regeneration technologies based on AOPs processes. Although there is considerable research on this topic, the economics and practicality of AOPs-regenerated carbon materials remain unsatisfactory, and reports on related industrial applications are still limited. Therefore, considering the economics, feasibility, and practicality of engineering implementation, there is an urgent need for single or combined AOPs processes based on oxidants to achieve efficient and economical regeneration and reuse of waste carbon materials such as adsorbed saturated carbon materials, providing technical support for actual industrial production processes. Summary of the Invention
[0007] This invention addresses the technical problem of poor economic efficiency in the regeneration and reuse of waste carbon materials such as adsorbed saturated carbon materials. Considering the differences in the advanced oxidation processes catalyzed by carbon materials and the reaction characteristics, economic efficiency, and practicality of different oxidants, it provides a stepwise autocatalytic oxidation regeneration method for carbon materials based on the coupled addition of oxidants.
[0008] To achieve the above objectives, the present invention adopts the following technical solution:
[0009] This invention provides a stepwise autocatalytic oxidation regeneration method for carbon materials based on the coupled addition of oxidants. A single oxidant or a mixture of oxidants is added according to the coupling law of the oxidants to achieve the simultaneous oxidation and degradation of pollutants during the in-situ regeneration of adsorbed saturated carbon materials; the coupling law refers to the oxidizing power of the oxidants.
[0010] In the above technical solution, the oxidant is selected from persulfate, perdisulfate, ozone, hydrogen peroxide or hypochlorite.
[0011] In the above technical solution, the addition method is either a one-time addition or a batch addition, and the interval between batch additions is generally more than 3 hours.
[0012] In the above technical solution, the oxidant is in the form of solid particles or liquid.
[0013] In the above technical solution, the carbon material includes one or more of activated carbon, activated coke, activated carbon fiber, graphite, graphene, diamond, biochar, and carbon nanotubes.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0015] This invention provides a cascaded autocatalytic oxidation regeneration method for carbon materials based on coupled oxidant addition. The oxidant is added according to its coupling principle to achieve synergistic utilization of the oxidant and derived oxidizing species. It is applicable not only to in-situ regeneration of carbon materials while simultaneously oxidizing and degrading various coexisting pollutants such as new pollutants, but also to ex-situ regeneration of carbon materials. It can be used for short-term rapid regeneration during production pauses, as well as for continuous and gradual regeneration in continuous production processes. It is easy to implement without altering existing structures, and the cost of cascaded autocatalytic oxidation regeneration is controllable and adjustable, superior to existing pyrolysis and other physical and chemical regeneration methods. Detailed Implementation
[0016] The following examples are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. The experimental methods in the following examples are conventional methods unless otherwise specified. The reagents used in the following examples are commercially available unless otherwise specified.
[0017] Example 1: Single oxidant-based stepwise autocatalytic oxidation regeneration of adsorbed saturated dry activated carbon
[0018] In this embodiment, commercially available persulfate (PDS), H2O2, and NaClO are used to achieve efficient regeneration of adsorbed saturated activated carbon through stepwise autocatalytic oxidation.
[0019] A 100 mL conical flask was selected, and 5.0 g of adsorption-saturated dry activated carbon (wet activated carbon was dried in an oven at 60℃ to obtain dry activated carbon) from the tertiary adsorption device for the secondary effluent deep purification of Zhengzhou Municipal Wastewater Treatment Plant was weighed. 20 mL of tap water and a certain amount of oxidant were added, and the mixture was regenerated in a constant-temperature shaker (25℃). The oxidants were added either all at once or in equal batches. The specific dosage, addition method, and regeneration efficiency of each oxidant are shown in Table 1.
[0020] As shown in Table 1, when NaClO (2 mL), H2O2 (2 mL), and PDS (0.2 g PDS) were added in a single batch, the regeneration efficiencies of the adsorbed saturated activated carbon reached 56.57%, 59.72%, and 83.31%, respectively. However, when NaClO (1 mL + 1 mL), H2O2 (1 mL + 1 mL), and PDS (0.1 g + 0.1 g) were added in batches, the regeneration efficiencies of the activated carbon reached 67.29%, 68.31%, and 84.19%, respectively. In other words, compared with adding each oxidant in a single batch, adding each oxidant in batches significantly improved the regeneration efficiency of the adsorbed saturated activated carbon, indicating that the batch-step autocatalytic oxidation regeneration efficiency of a single oxidant is high and has significant economic advantages.
[0021] Table 1. Regeneration conditions and regeneration efficiency of single oxidant-based stepwise autocatalytic oxidation
[0022]
[0023] Example 2: Combined use of H2O2 and PDS for stepwise autocatalytic oxidation regeneration of adsorbed saturated dry activated carbon
[0024] In this embodiment, commercially available H2O2 and PDS are added sequentially. PDS has a higher oxidizing power than H2O2, so as to achieve efficient regeneration of adsorbed saturated activated carbon through stepwise autocatalytic oxidation.
[0025] A 100 mL conical flask was selected, and 5.0 g of adsorption-saturated dry activated carbon from the tertiary adsorption unit of the secondary effluent deep purification process at Zhengzhou Municipal Wastewater Treatment Plant was weighed. 20 mL of tap water and a certain amount of oxidant were added, and the mixture was regenerated in a constant-temperature shaker (25℃). The oxidants were added in batches of equal / unequal amounts. The specific dosage, addition method, and regeneration efficiency of each oxidant are shown in Table 2.
[0026] As shown in Table 2, the regeneration efficiencies of the combinations of 1 mL H2O2 + 0.1 g PDS and 0.1 g PDS + 1 mL H2O2 reached 74.75% and 64.96%, respectively; the regeneration efficiencies of the combinations of 2 mL H2O2 + 0.2 g PDS and 0.2 g PDS + 2 mL H2O2 reached 90.5% and 84.19%, respectively. This indicates that when the adsorbed saturated activated carbon is first pre-oxidized with H2O2 and then deeply oxidized with PDS, its regeneration efficiency is significantly higher than that of the combination of pre-oxidized with PDS followed by deep oxidation with H2O2. This demonstrates that the stepwise oxidation regeneration strategy of pre-oxidation with H2O2 followed by deep oxidation with PDS has significant economic advantages and feasibility.
[0027] Table 2. Regeneration conditions and efficiency of H2O2 and PDS combined staged autocatalytic oxidation.
[0028]
[0029] Example 3: A series of autocatalytic oxidation methods using H2O2, NaClO, and PDS to regenerate saturated dry activated carbon.
[0030] In this embodiment, commercially available H2O2 / NaClO and PDS are added sequentially in a stepwise manner to achieve efficient regeneration of adsorbed saturated activated carbon through stepwise autocatalytic oxidation.
[0031] A 100 mL conical flask was selected, and 5.0 g of saturated activated carbon from the tertiary adsorption unit of the secondary effluent deep purification process at the Zhengzhou Municipal Wastewater Treatment Plant was weighed. 20 mL of tap water and a certain amount of oxidant were added, and the mixture was regenerated in a constant-temperature shaker (25℃). The oxidants were added in batches of equal / unequal amounts. The specific dosage, addition method, and regeneration efficiency of each oxidant are shown in Table 3.
[0032] As shown in Table 3, the overall regeneration efficiency of each oxidant combination significantly improved as the PDS dosage increased from 0.1 g to 0.2 g. Compared with the 1 mL H2O2 / 1 mL NaClO + 0.1 g PDS oxidant combination, the regeneration efficiency of the 2 mL H2O2 / 2 mL NaClO + 0.1 g PDS oxidant combination did not significantly improve, but instead showed a decreasing trend. The regeneration efficiencies of the 1 mL NaClO + 1 mL H2O2 + 0.1 g PDS and 1 mL H2O2 + 1 mL NaClO + 0.1 g PDS combinations reached 85.79% and 78.09%, respectively, while the regeneration efficiencies of the 2 mL NaClO + 2 mL H2O2 + 0.2 g PDS and 2 mL H2O2 + 2 mL NaClO + 0.2 g PDS combinations reached 92.07% and 87.37%, respectively. Therefore, it is evident that when the adsorbed saturated activated carbon is first oxidized by NaClO, then by H2O2, and finally by deep oxidation with PDS, its regeneration efficiency is significantly higher than that of the first H2O2 oxidation followed by NaClO oxidation and then deep oxidation with PDS. This indicates that the sequential stepwise oxidation regeneration strategy of NaClO + H2O2 + PDS has relatively high economic efficiency and feasibility.
[0033] Table 3. Regeneration conditions and efficiency of H2O2 / NaClO and PDS combined staged autocatalytic oxidation.
[0034]
[0035] Example 4: Autocatalytic oxidation regeneration of dry and wet adsorption saturated activated carbon using H2O2 / NaClO and PDS
[0036] In actual water treatment processes, adsorbed saturated activated carbon is wet during in-situ regeneration. To study the feasibility of using dried adsorbed saturated activated carbon in the experimental evaluation process, this embodiment compares the autocatalytic oxidation regeneration effects of dry adsorbed saturated activated carbon (dry activated carbon) and wet adsorbed saturated activated carbon (wet activated carbon) in different oxidation systems.
[0037] Select a 100 mL conical flask and weigh 5.0 g of adsorption-saturated dry activated carbon (wet activated carbon dried in an oven at 60℃ to obtain dry activated carbon) or the equivalent of 5.0 g of wet activated carbon from the tertiary adsorption unit for the secondary effluent deep purification of Zhengzhou wastewater treatment plant. Add 20 mL of tap water and a certain amount of oxidant, and regenerate in a constant temperature shaker (25℃). The oxidant is added either all at once or in equal batches. The specific dosage, addition method, and regeneration efficiency of each oxidant are shown in Table 4.
[0038] Table 4 shows that when using 0.1 g PDS alone for regeneration, the regeneration efficiency of wet activated carbon reaches 79.91%, higher than that of dry activated carbon (74.28%). In the 1 mL NaClO + 0.2 g PDS regeneration system, the regeneration efficiency of wet activated carbon further increases to 94.70%, higher than that of dry activated carbon (90.18%). In the 2 mL H2O2 + 0.2 g PDS system, the regeneration efficiency of wet activated carbon is 87.50%, slightly lower than that of dry activated carbon (90.5%). These results indicate that when using dry and wet activated carbon for regeneration experiments, the regeneration efficiency of wet activated carbon is generally not lower than that of dry activated carbon, and may even be higher. Therefore, dry activated carbon can be used to indirectly evaluate the in-situ regeneration effect through autocatalytic oxidation regeneration experiments.
[0039] Table 4. Regeneration conditions and efficiency of dry and wet activated coke staged autocatalytic oxidation.
[0040]
[0041] Example 5: Stepwise autocatalytic oxidation regeneration of adsorption-saturated activated carbon
[0042] Preparation of saturated activated carbon for adsorption: The activated carbon (AC) used in the experiment had a specific surface area of 1296.3 m². 2 / g, which is far higher than the specific surface area of 554.2 m² of activated char. 2 / g. Place 1g AC in 500 mL of 300 mg / L tetracycline solution and adsorb at a constant temperature for 24 h. Discard the supernatant, filter and wash with distilled water. Place the washed activated carbon in an oven at 60 ℃ and dry for 3 h. Store in a sealed bag for later use.
[0043] Select a 100 mL conical flask, weigh 5.0 g of the above-prepared saturated activated carbon, add 20 mL of tap water and a certain amount of oxidant, and regenerate in a constant temperature shaker (25℃). The catalysts were added either all at once or in batches of equal / unequal amounts. The specific dosage, addition method, and regeneration efficiency of each catalyst are shown in Table 5.
[0044] Table 5 shows that the regeneration efficiencies of 2 mL NaClO and 1 mL + 1 mL NaClO for saturated activated carbon reached 26.31% and 33.32%, respectively; the regeneration efficiencies of 0.2 g PDS and 0.1 g + 0.1 g PDS for saturated activated carbon reached 55.53% and 60.88%, respectively. These results indicate that adding NaClO and PDS in stages is superior to adding them all at once. Furthermore, the regeneration efficiencies of the combinations 2 mL NaClO + 0.1 g PDS and 0.1 g PDS + 2 mL NaClO reached 52.47% and 45.46%, respectively. The regeneration efficiency of saturated activated carbon regenerated by first oxidizing with NaClO and then deeply oxidizing with PDS was significantly higher than that of first oxidizing with PDS and then with NaClO. This suggests that for tetracycline-saturated activated carbon, a certain stepwise autocatalytic oxidation regeneration effect still exists when regenerating it through oxidants or combinations of oxidants, demonstrating relatively high economic efficiency and feasibility.
[0045] Table 5. Tetracycline-adsorbed saturated activated carbon (AC) staged autocatalytic oxidation regeneration conditions and regeneration efficiency
[0046]
[0047] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.
Claims
1. A method for the graded autocatalytic oxidation and regeneration of carbon materials based on coupled oxidant addition, characterized in that, Based on the coupling principle of oxidants, single or mixed oxidants are added to achieve simultaneous oxidative degradation of pollutants during the in-situ regeneration of adsorbed saturated carbon materials; the coupling principle refers to the oxidizing power of the oxidants.
2. The method for graded autocatalytic oxidation and regeneration of carbon materials based on coupled oxidant addition according to claim 1, characterized in that, The oxidant is selected from persulfate, perdisulfate, ozone, hydrogen peroxide, or hypochlorite.
3. The method for graded autocatalytic oxidation and regeneration of carbon materials based on coupled oxidant addition according to claim 1, characterized in that, The method of application is either a one-time application or an application in batches.
4. The method for graded autocatalytic oxidation and regeneration of carbon materials based on coupled oxidant addition according to claim 1, characterized in that, The oxidant is in the form of solid particles or liquid.
5. The method for graded autocatalytic oxidation and regeneration of carbon materials based on coupled oxidant addition according to claim 1, characterized in that, The carbon material includes one or more of activated carbon, activated coke, activated carbon fiber, graphite, graphene, diamond, biochar, and carbon nanotubes.