A carbon catalyst based on sludge in black and odorous water bodies, its preparation method and application

Abstract

The present application belongs to the technical field of catalyst preparation, and relates to a preparation method and application of a black and odorous water sludge-based carbon catalyst. The preparation method of the black and odorous water sludge-based carbon catalyst comprises the following steps: (1) mixing, drying and grinding black and odorous water sludge and non-sludge biomass materials to obtain carbon-increased sludge; and (2) activating the carbon-increased sludge with an activator, pyrolyzing and cooling the carbon-increased sludge in an inert atmosphere to obtain the black and odorous water sludge-based carbon catalyst. The present application improves the carbon content of sludge carbon, reduces the yield, ash content, conductivity and element ratios of H / C, N / C and O / C of sludge carbon by co-pyrolyzing black water sludge and non-sludge biomass materials. In addition, co-pyrolysis reduces the content and toxicity of heavy metals in biochar. Co-pyrolysis of black and odorous water sludge and non-sludge biomass materials rich in C elements not only simultaneously disposes the sludge and non-sludge biomass materials, but also improves the C element content of biochar, thereby improving the catalytic ozone activity of the biochar.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a carbon catalyst based on sludge from black and odorous water bodies, its preparation method, and its application. Background Technology

[0002] In recent years, my country's urbanization and industrialization have increased, but the supporting urban infrastructure is inadequate. This has led to a large amount of domestic sewage and industrial wastewater being discharged into natural water bodies. The pollutants exceed the water bodies' self-purification capacity, resulting in black and odorous water bodies. The silt in these black and odorous water bodies is both an accumulation of pollutants and a source of continuous release of pollutants into the water.

[0003] Furthermore, the high nitrogen and phosphorus content in black and odorous water bodies leads to the proliferation of algae, reeds, and aquatic plants. Unremoved algae, reeds, and aquatic plants accelerate their reproduction and decay, exacerbating the black and odorous condition of the water. Therefore, these plants need to be regularly removed. The remediation of black and odorous water bodies often employs techniques such as artificial wetlands, ecological floating islands, and ecological revetments. By planting emergent and submerged plants to restore the water body, regular plant removal is also necessary.

[0004] Dredging and sludge removal are effective measures to eliminate internal pollution sources in black and odorous water bodies. Currently, the main methods for disposing of sludge from these water bodies include dehydration, sintering and solidification, land application, building material utilization, and landfilling. However, sludge from black and odorous water bodies contains pathogenic microorganisms, parasites (eggs), heavy metals, and persistent organic matter, which negatively impacts landfilling and land application. Furthermore, the sludge has a high water content and sand content, requiring higher pressure and pyrolysis temperatures to produce bricks / pottery, which increases the cost of sludge disposal. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, the present invention aims to provide a method for preparing a carbon catalyst based on sludge from black and odorous water bodies. This invention involves co-pyrolyzing black water body sludge with non-sludge-type biomass materials to increase the carbon content of the sludge carbon and reduce its yield, ash content, electrical conductivity, and the elemental ratios of H / C, N / C, and O / C. Furthermore, co-pyrolysis reduces the content and toxicity of heavy metals in the biochar. Co-pyrolyzing black and odorous water body sludge with carbon-rich non-sludge-type biomass materials not only simultaneously treats both sludge and non-sludge-type biomass materials but also increases the carbon content of the sludge biochar, thereby enhancing its ozone-catalyzing activity.

[0006] To achieve the above objectives, in a first aspect of the present invention, a preparation method is provided, comprising:

[0007] (1) Mix black and odorous water sludge with non-sludge biomass materials, dry and grind to obtain carbon-enriched sludge;

[0008] (2) After the carbon-enriched sludge is activated, it is pyrolyzed and cooled in an inert atmosphere to obtain a carbon catalyst based on sludge in black and odorous water bodies.

[0009] As a preferred embodiment of the present invention, in step (1), the weight ratio of the black and odorous water body sludge to the non-sludge type biomass material is 1:(0.5-5).

[0010] As a preferred embodiment of the present invention, in step (1), the carbon-enriched sludge has a mesh size of 18 to 200 mesh.

[0011] As a preferred embodiment of the present invention, in step (2), the specific steps for activating the carbon-enriched sludge are as follows:

[0012] The carbon-enriched sludge and activator are dissolved in deionized water and mixed to prepare a mixed solution. After soaking at room temperature for 2 to 72 hours, the solution is filtered and dried. The activator is at least one of H2SO4, H3PO4 and ZnCl2, or at least one of NaOH, KOH, NaHCO3, Na2CO3, KHCO3 and K2CO3.

[0013] As a preferred embodiment of the present invention, in step (2), the mass ratio of the activator to the carbon-enriched sludge is (0.1-5):1; preferably (1-2):1.

[0014] As a preferred embodiment of the present invention, in step (2), the pyrolysis temperature is 300-1000℃, the time is 0.5-6h, and the heating rate is 3-20℃ / min.

[0015] As a preferred embodiment of the present invention, the method further includes, after step (2), loading the black and odorous water body sludge-based carbon catalyst with metal oxides by impregnation method;

[0016] The metal in the metal oxide is one or more of Fe, Co, Ni, Mn, and Ce, and the metal content in the metal-supported carbon catalyst is 0.1% to 20 wt%.

[0017] As a preferred embodiment of the present invention, after step (2), the carbon catalyst based on sludge in the black and odorous water body is acid-washed, washed with water until the pH is neutral, and then dried.

[0018] In another aspect of the present invention, a carbon catalyst based on sludge in black and odorous water bodies is provided, prepared by the method described in any one of the first aspects of the present invention.

[0019] In another aspect of the invention, the application of a carbon catalyst based on sludge in black and odorous water bodies, as described in the second aspect of the invention, in catalytic ozone oxidation is provided.

[0020] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0021] (1) This invention provides a method for preparing a carbon catalyst based on sludge from black and odorous water bodies. The sludge contains a large amount of organic matter and minerals such as N, P, and K, and also contains a certain amount of heavy metals such as Cu, Zn, Ni, Cr, Pb, Cd, As, and Hg. By co-pyrolyzing the sludge from black and odorous water bodies and non-sludge-type biomass materials, on the one hand, the surface functional groups of the sludge carbon materials serve as active sites for the catalytic process. These characteristics give the co-pyrolyzed carbon higher adsorption and catalytic performance, while improving the pollution problems of sludge and non-sludge-type biomass materials. On the other hand, pyrolysis can also increase the graphitization degree of the carbon-based catalyst. Increasing the graphitization degree is beneficial to the electron transfer capacity of the catalyst. During the calcination process, some heavy metals coordinate with carbon or nitrogen to form local active sites, thereby enhancing the catalytic activity of the catalyst.

[0022] (2) The present invention uses pyrolysis activation technology to treat sludge, which can reduce the microorganisms in sludge, fix the heavy metals in sludge, and realize the reduction and harmlessness of sludge.

[0023] This invention utilizes dredging to obtain sludge, reducing endogenous pollution in black and odorous water bodies and achieving water body remediation. The sludge-based carbon catalyst prepared in this invention kills pathogenic microorganisms and parasites (eggs) in the sludge through pyrolysis, achieving sludge reduction and harmlessness. Furthermore, the activated pyrolysis of the sludge can fix heavy metals in the sludge, reducing heavy metal leaching, which is environmentally friendly and provides an effective disposal method for dredged sludge. The preparation of this sludge-based carbon catalyst provides a disposal method for dredged sludge, contributing to the treatment of black and odorous water bodies. The carbon catalyst exhibits good catalytic performance and can reduce the cost of water and wastewater treatment while increasing the carbon resource utilization rate of the sludge.

[0024] (3) In this invention, aquatic plants of black and odorous water bodies and shoreline plants of black and odorous water body remediation are further used as carbon-enriching agents. On the one hand, this provides a reliable treatment method for these plants, and at the same time realizes the efficient utilization of difficult-to-treat sludge and waste biomass. On the other hand, the carbon resources in the plants are utilized to increase the carbon content in the catalyst, thereby obtaining a sludge-based carbon catalyst with high catalytic activity.

[0025] In addition, waste biomass such as kitchen waste, bran, vegetables, aquatic plants, reeds, algae, and straw are rich in carbon. One or more of these can be used as carbon enrichment agents to prepare a carbon catalyst with high catalytic activity. By co-pyrolyzing these substances with sludge from black and odorous water bodies, the carbon content of the sludge-based carbon catalyst is increased, thereby improving its catalytic performance. The preparation process has low cost, thus reducing the cost of catalytic ozone oxidation for wastewater treatment.

[0026] (4) The carbon catalyst based on sludge in black and odorous water bodies prepared by this invention has a mesoporous structure and abundant surface functional groups, exhibiting good adsorption performance. The larger pore structure facilitates the diffusion of ozone and organic matter to the catalyst surface, thereby promoting the reaction between ozone, catalyst, and organic matter and improving its catalytic performance. Furthermore, this carbon catalyst based on sludge in black and odorous water bodies has strong adaptability to catalytic applications; in the embodiments of this invention, its catalytic and adsorption performance in secondary effluent is verified to be good.

[0027] For example, carbon catalysts based on sludge from black and odorous water bodies can catalyze ozone to generate more hydroxyl radicals, improving ozone oxidation efficiency and reducing wastewater treatment costs. Compared to ozone, which is a strong oxidant, ozone in water treatment not only disinfects but also oxidizes (removing odors, decolorizing, and oxidizing micro-pollutants, etc.). However, ozone oxidation alone has drawbacks such as selective oxidation and low ozone utilization. Attached Figure Description

[0028] Figure 1 This is a graph illustrating the change in DEA concentration of organic matter over time during the sludge carbon catalytic ozone process, as exemplified in Embodiment 1 of the present invention.

[0029] Figure 2 This is a graph illustrating the change in liquid-phase ozone concentration over time during the sludge carbon catalytic ozone process, as exemplified in Embodiment 1 of the present invention.

[0030] Figure 3 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon-catalytic ozone process of carbon-enriched sludge in direct pyrolysis, as exemplified in Embodiment 2 of the present invention.

[0031] Figure 4 This is a graph illustrating the change in liquid-phase ozone concentration over time in the carbon-catalyzed ozone process of carbon-enriched sludge during direct pyrolysis, as exemplified in Embodiment 2 of the present invention.

[0032] Figure 5 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon catalytic ozone process in ZnCl2-activated carbonized sludge, as exemplified in Example 3 of the present invention.

[0033] Figure 6 This is a graph illustrating the change in liquid-phase ozone concentration over time during the carbon catalytic ozone process of ZnCl2-activated carbonized sludge, as exemplified in Example 3 of the present invention.

[0034] Figure 7 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon adsorption process of ZnCl2-activated carbonized sludge, as exemplified in Example 3 of the present invention.

[0035] Figure 8This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon catalytic ozone process of ZnCl2-activated carbonized sludge, as exemplified in Example 4 of the present invention.

[0036] Figure 9 This is a graph illustrating the change in liquid-phase ozone concentration over time during the carbon catalytic ozone process of ZnCl2-activated carbonized sludge, as exemplified in Example 4 of the present invention.

[0037] Figure 10 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon adsorption process of ZnCl2-activated carbonized sludge, as exemplified in Example 4 of the present invention.

[0038] Figure 11 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon-catalytic ozone process of H3PO4 or KOH activated carbonized sludge, as exemplified in Example 5 of the present invention.

[0039] Figure 12 This is a graph illustrating the change in liquid-phase ozone concentration over time during the carbon catalytic ozone process of H3PO4 or KOH activated carbonized sludge, as exemplified in Example 5 of the present invention.

[0040] Figure 13 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon adsorption process of H3PO4 or KOH activated carbonized sludge, as exemplified in Example 5 of the present invention.

[0041] Figure 14 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon catalytic ozone process in ZnCl2-activated carbonized sludge, as exemplified in Example 6 of the present invention.

[0042] Figure 15 This is a graph illustrating the change in liquid-phase ozone concentration over time during the carbon catalytic ozone process of ZnCl2-activated carbonized sludge, as exemplified in Example 6 of the present invention.

[0043] Figure 16 This is a graph illustrating the change in DEA concentration of organic matter over time during the carbon adsorption process of ZnCl2-activated carbonized sludge, as exemplified in Example 6 of the present invention.

[0044] Figure 17 This is an example of the adsorption-desorption curve of ZnCl2-activated carbon-enriched sludge carbon in Embodiment 6 of the present invention.

[0045] Figure 18 This is a pore size distribution curve of carbon in ZnCl2-activated carbonized sludge, as exemplified in Embodiment 6 of the present invention.

[0046] Figure 19 Examples of different types of loaded metal oxides in Embodiment 7 of the present invention are SC 1.5 Curve showing the change in DEA concentration of organic matter over time during the catalytic ozone process;

[0047] Figure 20 Examples of different types of loaded metal oxides in Embodiment 7 of the present invention are SC 1.5 Curve showing the change in liquid-phase ozone concentration over time during the catalytic ozone process;

[0048] Figure 21 Examples of different types of loaded metal oxides in Embodiment 7 of the present invention are SC 1.5 Curve showing the change in DEA concentration of organic matter over time during the adsorption process;

[0049] Figure 22 SC with different loading ratios of metal oxides, as exemplified in Embodiment 8 of the present invention 1.5 Curve showing the change in DEA concentration of organic matter over time during the catalytic ozone process;

[0050] Figure 23 SC with different loading ratios of metal oxides, as exemplified in Embodiment 8 of the present invention 1.5 Curve showing the change in liquid-phase ozone concentration over time during the catalytic ozone process;

[0051] Figure 24 SC with different loading ratios of metal oxides, as exemplified in Embodiment 8 of the present invention 1.5 Curve showing the change in DEA concentration of organic matter over time during the adsorption process;

[0052] Figure 25 SC, an example of a bimetallic oxide-loaded material from Embodiment 9 of the present invention 1.5 Curve showing the change in DEA concentration of organic matter over time during the catalytic ozone process;

[0053] Figure 26 SC, an example of a bimetallic oxide-loaded material from Embodiment 9 of the present invention 1.5 Curve showing the change in liquid-phase ozone concentration over time during the catalytic ozone process;

[0054] Figure 27 SC, an example of a bimetallic oxide-loaded material from Embodiment 9 of the present invention 1.5 Curve showing the change in DEA concentration of organic matter over time during the adsorption process;

[0055] Figure 28 SC in the secondary effluent of Embodiment 10 of the present invention 1.5 and Ce 1wt% - Ni 1wt% / SC 1.5 Curve showing the change in DEA concentration of organic matter over time during the catalytic ozone process;

[0056] Figure 29 SC in the secondary effluent of Embodiment 10 of the present invention 1.5 and Ce 1wt% - Ni 1wt% / SC 1.5Curve showing the change in liquid-phase ozone concentration over time during the catalytic ozone process;

[0057] Figure 30 SC in the secondary effluent of Embodiment 10 of the present invention 1.5 and Ce 1wt% - Ni 1wt% / SC 1.5 The graph showing the change in DEA concentration of organic matter over time during the adsorption process.

[0058] The accompanying figures are described below:

[0059] In the attached diagram, "O3" represents the test of simple ozone oxidation; "O3 + silt carbon 700℃" represents the test of ozone catalysis by silt carbon synthesized from pyrolysis of silt in black and odorous water bodies at 700℃.

[0060] The figures "O3 + carbonized sludge carbon 500 / 700 / 900℃ (35-50 mesh or 50-100 mesh)" and "carbonized sludge carbon 500 / 700 / 900℃ (35-50 mesh or 50-100 mesh)" in the attached diagrams represent the tests and adsorption tests of carbonized sludge carbon catalyzed by carbonization synthesis at the corresponding temperatures using carbonized sludge of the selected mesh sizes.

[0061] The attached figures show "O3 + carbonized sludge carbon - H3PO4 / KOH / ZnCl2 (0.2 / 0.6 / 1.0 / 2.0 / 3.0 / 4.0) 500℃" and "carbonized sludge carbon - H3PO4 / KOH / ZnCl2 (0.2 / 0.6 / 1.0 / 2.0 / 3.0 / 4.0) 500℃", representing the ozone catalytic and adsorption tests of carbonized sludge carbon synthesized at 500℃ using different activators (H3PO4 / KOH / ZnCl2) and carbonized sludge at different mass ratios (0.2 / 0.6 / 1.0 / 2.0 / 3.0 / 4.0).

[0062] SC0 and SC in the attached diagram 1.5 or SC 2.0 The subscripts represent the mass ratios of activator to carbon-enriched sludge as 0, 1.5, and 2.0, respectively; "O3+SC 0 / 1.0 / 1.5 / 2.0 "and "SC 0 / 1.0 / 1.5 / 2.0 "The tests and adsorption tests of carbon-catalyzed ozone from carbon-enriched sludge synthesized with different activators and mass ratios of carbon-enriched sludge are respectively; "raw material" refers to unactivated carbon-enriched sludge.

[0063] The attached diagram shows "O3+Fe / Ce / Ni / Co 1 / 2 / 3 / 5wt% / SC". 1.5 ” and “Fe / Ce / Ni / Co 1 / 2 / 3 / 5wt% / SC 1.5"The tests and adsorption tests were conducted on ozone catalyzed by synthesizing carbon-enriched sludge with different activator-to-carbon-enriched sludge mass ratios and carbon loadings of different contents of Fe, Ce, Ni, or Co."

[0064] The attached diagram shows "O3+Fe / Ce / Co 1wt%-Ni 1wt% / SC". 1.5 ” and “Fe / Ce / Co 1wt%-Ni 1wt% / SC 1.5 "Tests and adsorption tests were conducted on bimetallic catalytic ozone with different carbon loading contents in carbon-enriched sludge synthesized with different activator-to-carbon-enriched sludge mass ratios." Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0066] In an embodiment of the present invention, a method for preparing a carbon catalyst based on sludge from black and odorous water bodies includes the following specific steps:

[0067] Step 1: Pretreatment: Mix the black and odorous water body sludge with non-sludge-type biomass materials for composting, drying, and grinding to form dry carbon-enriched sludge for later use. The mesh size of the ground carbon-enriched sludge is 18-200 mesh. The dry weight ratio of the black and odorous water body sludge to the non-sludge-type biomass materials is controlled at 1:(0.5-5).

[0068] The non-sludge-type biomass material comprises one or more of the following: aquatic plants from polluted water bodies, shoreline plants from polluted water body remediation, kitchen waste, bran, vegetables, aquatic plants, reeds, algae, and straw. Aquatic plants from polluted water bodies and shoreline plants from polluted water body remediation are preferred as carbon raisers.

[0069] Step 2 Activation: Mix the activator with the carbon-enriching sludge, add an appropriate amount of deionized water, soak at room temperature, and then dry. Prepare a mixed solution of 0.1–10 mol / L, soak at room temperature for 2–72 hours, remove the supernatant, and dry. The activator can be one of H2SO4, H3PO4, NaOH, KOH, ZnCl2, NaHCO3, Na2CO3, KHCO3, or K2CO3; or two or more of the above activators can be selected as a mixed activator, such as a mixture of H2SO4 and H3PO4, NaOH and KOH, ZnCl2 and H2SO4, ZnCl2 and H3PO4, NaOH and Na2CO3, NaHCO3 and Na2CO3, KOH and K2CO3, KHCO3 and K2CO3, H2SO4, H3PO4 and ZnCl2, NaOH, KOH and KHCO3, etc. The total weight of the activator to the mass ratio of carbon in the sludge should be maintained at (0.1-5):1, preferably (1-2):1.

[0070] Step 3: Carbonization: The activated material is filled with an inert gas, such as nitrogen, argon, or helium, under vacuum conditions. The heating rate is maintained at 3–20 °C / min. The material is then pyrolyzed and carbonized at 300–1000 °C for 0.5–6 hours and then cooled to obtain crude carbon, which is a carbon catalyst based on sludge in black and odorous water bodies.

[0071] Step 4 Post-treatment: Wash the crude carbonate with water until the pH is neutral, and then dry it.

[0072] Preferably, the crude carbon obtained in step four is used as a support to prepare a sludge-based carbon catalyst loaded with metal oxides using an equal-volume impregnation method. The metal oxide is one or more of Fe, Co, Ni, Mn, and Ce, and the proportion of the loaded metal is 0.1% to 20 wt%.

[0073] Furthermore, the specific surface area of ​​the sludge-based carbon catalyst for black and odorous water bodies prepared by the above method is 21.4–913.4 m². 2 / g. Pore volumes for pores smaller than 2nm range from 0.01 to 0.41cm³. 3 / g, with pore sizes ranging from 2 to 300 nm and pore volumes ranging from 0.09 to 0.80 cm³. 3 / g.

[0074] The carbon catalyst based on sludge from black and odorous water bodies provided in this invention was applied to ozone catalysis and adsorption experiments. Specifically:

[0075] Ozone preparation: Oxygen is introduced into the ozone generator, and the gas is diffused into the 0℃ ultrapure water through the aeration head. After aeration for 5-10 minutes, once uniform bubbles are observed emerging from the 0℃ ultrapure water, the ozone generator is turned on. After aeration for about 30 minutes, the system tends to stabilize, and the ozone water is close to saturation. The absorbance of the ozone water at 260nm is measured to determine the ozone concentration.

[0076] Catalytic ozone experiment: 95 mL of ultrapure water / actual wastewater was measured, and 3–10 μM deethylatrazine (DEA) and buffer salt were added. The pH was adjusted to approximately 3.0–8.0 using NaOH and HClO4. The total volume of the reaction solution was controlled at 120 mL, and the ozone concentration at 1–7 mg / L. Based on the measured saturated ozone concentration, the volume of saturated ozone water to be added and the volume of ultrapure water / actual wastewater to be replenished were calculated. Ultrapure water / actual wastewater, 0–120 mg / L catalyst, and saturated ozone water were added sequentially. Timing was started after the addition of saturated ozone water. The catalytic ozone experiment was conducted at a constant temperature of 25℃ and with magnetic stirring at 400 rpm. After a certain reaction time, water samples were taken to measure the liquid phase ozone concentration and the concentration of DEA (deoxygenated organic matter).

[0077] Adsorption experiment: Initially, 3–10 μM DEA and buffer salt were added. The pH was adjusted to approximately 3.0–8.0 using NaOH and HClO4, with a total reaction volume of 120 mL. Timing began after adding 0–120 mg / L catalyst. The adsorption experiment was conducted at a constant temperature of 25 °C with magnetic stirring at 400 rpm. After a certain reaction time, water samples were taken to measure the DEA concentration of organic matter.

[0078] The specific implementation method is as follows:

[0079] Example 1:

[0080] Using sludge from black and odorous water bodies as raw material, the sludge was dried and sieved to select raw materials with a mesh size of 50-100. Then, the raw materials were pyrolyzed at 700℃ for 2 hours under a nitrogen atmosphere with a heating rate of 10℃ / min to prepare synthetic sludge carbon.

[0081] The above-mentioned sludge carbon was applied to catalytic ozone production. The experimental conditions were controlled as follows: initial ozone concentration of 5 mg / L, sludge carbon dosage of 100 mg / L, deethylated atrazine (DEA) concentration of 3 μM, temperature of 25℃, 5 mM borate buffer, and pH adjusted to 7.0 with HClO4 and NaOH.

[0082] like Figure 1 and Figure 2 As shown, the catalytic ozone performance of sludge carbon synthesized by direct pyrolysis at 700℃ is slightly lower than that of ozone alone.

[0083] Example 2:

[0084] Carbon-enriched sludge was prepared by mixing and composting sludge and non-sludge biomass materials in a mass ratio of 1:1.5. After drying, the sludge was sieved to select raw materials with mesh sizes of 35–50 mesh and 50–100 mesh, respectively. The non-sludge biomass materials were obtained at a weight ratio of straw:vegetables:wheat bran of 3:1:1. Then, the above raw materials were pyrolyzed at 500℃, 700℃, or 900℃ for 2 hours under a nitrogen atmosphere at a heating rate of 10℃ / min to prepare synthetic carbon-enriched sludge carbon.

[0085] The above-mentioned carbon-enriched sludge carbon was applied to catalytic ozone production. The experimental conditions were controlled as follows: initial ozone concentration of 5 mg / L, carbon-enriched sludge carbon dosage of 100 mg / L, deethylated atrazine (DEA) concentration of 3 μM, temperature of 25℃, 5 mM borate buffer, and pH adjusted to 7.0 with HClO4 and NaOH.

[0086] like Figure 3 and Figure 4 As shown, the catalytic ozone-generating performance of carbon materials prepared by direct pyrolysis of carbon-enriched sludge or reeds is slightly higher than that of ozone alone. Comparing the catalytic ozone-generating performance of carbon-enriched sludge at 500℃ (35–50 mesh) and carbon-enriched sludge at 500℃ (50–100 mesh), it was found that their ozone-generating performance was almost identical. Comparing the catalytic performance of carbon-enriched sludge at 500℃ (50–100 mesh), 700℃ (50–100 mesh), and 900℃ (50–100 mesh), it was found that the pyrolysis temperature has a relatively small impact on the catalytic performance. Specific Implementation Example 3:

[0088] Carbon-enriching sludge obtained by mixing and composting sludge and non-sludge biomass materials with a mass ratio of 1:1.5 was dried and screened to select 50-100 mesh carbon-enriching sludge. The non-sludge biomass materials were obtained according to a weight ratio of straw:vegetables:wheat bran of 3:1:1.

[0089] Then, using ZnCl2 as an activator, the impregnation ratio (i.e., the mass ratio of activator to carbon-enriched sludge) was controlled at 1, 2, or 3, and the supernatant was removed and dried after soaking for 24 hours. Under a nitrogen atmosphere, the temperature was increased at a rate of 10℃ / min, and the mixture was pyrolyzed at 500℃ for 2 hours. Then, it was washed with 3M HCl and then washed with water until neutral, finally synthesizing the sludge-based carbon catalyst for black and odorous water bodies.

[0090] The above-mentioned carbon catalyst based on sludge from black and odorous water bodies was applied to catalyze ozone. The experimental conditions were: initial ozone concentration of 5 mg / L, carbon dosage of 100 mg / L, DEA concentration of 3 μM, temperature of 25℃, 2 mM carbonate buffer, and pH adjusted to 7.0 with HClO4 and NaOH.

[0091] like Figure 5 , Figure 6 and Figure 7 As shown, carbon-enriched sludge was activated with ZnCl2 as an activator, with impregnation ratios of 1, 2, or 3. After removing the supernatant and drying, carbon-enriched sludge carbon-ZnCl2(1.0)500℃, carbon-enriched sludge carbon-ZnCl2(2.0)500℃, and carbon-enriched sludge carbon-ZnCl2(3.0)500℃ were synthesized by pyrolysis. As can be seen from the figure, the catalytic performance of carbon materials dried after removing the supernatant with different impregnation ratios is almost the same.

[0092] Example 4:

[0093] Carbon-enriching sludge obtained from the mixing of sludge and non-sludge biomass materials in a mass ratio of 1:1.5 was dried and screened to select 50-100 mesh carbon-enriching sludge. The non-sludge biomass materials were composted according to the weight ratio of straw:vegetables:wheat bran of 3:1:1.

[0094] Then, using ZnCl2 as an activator, the impregnation ratio (i.e., the mass ratio of activator to carbon-enriched sludge) was controlled at 0.2, 0.6, 1.0, 2.0, or 4.0, and the sludge was directly dried after soaking for 24 hours. Under a nitrogen atmosphere, the sludge was pyrolyzed at 500℃ for 2 hours at a heating rate of 10℃ / min. The sludge was then washed with 3M HCl and then with water until neutral, ultimately synthesizing a carbon catalyst based on black and odorous water sludge.

[0095] The above-mentioned carbon catalyst based on sludge from black and odorous water bodies was applied to catalyze ozone. The experimental conditions were: initial ozone concentration of 5 mg / L, carbon dosage of 100 mg / L, DEA concentration of 3 μM, temperature of 25℃, 2 mM carbonate buffer, and pH adjusted to 7.0 with HClO4 and NaOH.

[0096] like Figure 8 , Figure 9 and Figure 10 As shown, carbon-enriching sludge was activated using ZnCl2 as an activator, with impregnation ratios of 0.2, 0.6, 1.0, 2.0, or 4.0. The sludge was then directly dried and pyrolyzed to prepare a carbon catalyst based on black and odorous water sludge. (Comparison) Figure 5 , Figure 6 and Figure 7 It can be found that, compared with the drying of supernatant after ZnCl2 impregnation and direct drying, the carbon material prepared by direct drying after ZnCl2 impregnation has better catalytic and adsorption performance. The catalytic performance improves with the increase of impregnation ratio, but when the impregnation ratio is greater than 2.0, the adsorption performance decreases with the increase of impregnation ratio.

[0097] Example 5:

[0098] Carbon-enriching sludge obtained by mixing and composting sludge and non-sludge biomass materials with a mass ratio of 1:1.5 was dried and screened to select 50-100 mesh carbon-enriching sludge. The non-sludge biomass materials were obtained according to a weight ratio of straw:vegetables:wheat bran of 3:1:1.

[0099] Using H3PO4 and KOH as activators, and controlling the impregnation ratio (i.e., the mass ratio of activator to carbon-enriched sludge) to be 0.5, 1.0, or 2.0 respectively, the sludge was soaked for 24 hours and then directly dried. Under a nitrogen atmosphere, the sludge was pyrolyzed at 500℃ for 2 hours at a heating rate of 10℃ / min. The sludge was then washed with 3M HCl and then with water until neutral, ultimately synthesizing a carbon catalyst based on black and odorous water sludge.

[0100] The above-mentioned carbon catalyst based on sludge from black and odorous water bodies was applied to catalyze ozone. The experimental conditions were: initial ozone concentration of 5 mg / L, carbon dosage of 100 mg / L, DEA concentration of 3 μM, temperature of 25℃, 2 mM carbonate buffer, and pH adjusted to 7.0 with HClO4 and NaOH.

[0101] like Figure 11 , Figure 12 and Figure 13 As shown, carbon materials synthesized by activating carbon-enriching sludge with H3PO4 or KOH as activators, and then directly drying and pyrolyzing it have certain catalytic ozone activity.

[0102] Example 6:

[0103] Carbon-enriched sludge, obtained by mixing and composting sludge and non-sludge biomass materials in a 1:2 mass ratio, was dried and sieved, with 50-100 mesh sludge selected. The non-sludge biomass materials were obtained at a weight ratio of straw:vegetables:wheat bran of 15:10:4. The carbon material obtained by pyrolyzing the carbon-enriched sludge at 500℃ for 2 hours under a nitrogen atmosphere at a heating rate of 10℃ / min was named SC. SC was washed with 3M HCl and then washed with water until neutral to obtain SC0. Activation with 3M ZnCl2 impregnation at ratios of 1.0, 1.5, or 2.0, followed by pyrolysis at 500℃ for 2 hours under a nitrogen atmosphere at a heating rate of 10℃ / min, and washing with 3M HCl and then washing with water until neutral, yielded SC0 and SC, respectively. 1.5 SC 2.0 (where the subscript represents the impregnation ratio).

[0104] The experimental conditions for controlling catalytic ozone were as follows: initial ozone concentration of 5 mg / L, carbon dosage of 80 mg / L, DEA concentration of 8 μM, temperature of 25℃, 2 mM carbonate buffer, and pH adjusted to 7.0 with HClO4 and NaOH.

[0105] like Figure 14 , Figure 15 and Figure 16 As shown, SC prepared by ZnCl2 activation 1.0 SC 1.5 and SC 2.0 It exhibits good catalytic and adsorption properties, and these properties increase with the increase of the ZnCl2 impregnation ratio.

[0106] The characterization results of the pyrolyzed raw materials and carbon materials in Example 6 are shown in Table 1. Figure 17 and Figure 18 As shown, it can be observed that with the increase of the ZnCl2 impregnation ratio, the specific surface area of ​​the synthesized carbon material increases, and the proportion of mesoporous pores increases.

[0107] Table 1. Specific surface area and pore size analysis of raw materials and carbon materials from pyrolysis.

[0108]

[0109] Example 7:

[0110] Using SC in Example 6 1.5 Using a metal carrier with a loading of 2 wt%, the loaded metal oxides are Fe, Co, Ce, or Ni, respectively. After adding a metal nitrate solution, the mixture is sonicated for 30 min, soaked at room temperature for 12 h, and then dried. Fe / SC is then prepared by pyrolysis at 400℃ for 3 h under a nitrogen atmosphere with a heating rate of 5℃ / min. 1.5 Co / SC 1.5 Ce / SC 1.5 and Ni / SC 1.5 .

[0111] The experimental conditions for controlling catalytic ozone were as follows: initial ozone concentration of 5 mg / L, carbon dosage of 80 mg / L, DEA concentration of 8 μM, temperature of 25℃, use of 3 mM phosphate buffer, and pH adjustment to 6.5 with HClO4 and NaOH.

[0112] like Figure 19 , Figure 20 and Figure 21 As shown, compared to O3+SC 1.5 Loading Fe, Ce, Co, or Ni improves SC 1.5 It retains its catalytic performance, but its adsorption performance decreases slightly.

[0113] Example 7:

[0114] Using SC in Example 6 1.5Using a carrier, the metal types were 1wt%, 2wt%, 3wt%, or 5wt%, and the metal oxide type was Ni. After adding a metal nitrate solution, the mixture was sonicated for 30 min, soaked at room temperature for 12 h, and dried. Then, it was pyrolyzed at 400℃ for 3 h under a nitrogen atmosphere with a heating rate of 5℃ / min.

[0115] The experimental conditions for controlling catalytic ozone were as follows: initial ozone concentration of 5 mg / L, carbon dosage of 80 mg / L, DEA concentration of 8 μM, temperature of 25℃, use of 3 mM phosphate buffer, and pH adjustment to 6.5 with HClO4 and NaOH.

[0116] like Figure 22 , Figure 23 and Figure 24 As shown, Ni 2wt% / SC 1.5 It has good catalytic performance.

[0117] Example 9:

[0118] Using SC in Example 6 1.5 Using a substrate, bimetallic oxides of Ce / Ni, Fe / Ni, or Co / Ni were loaded. After adding a metal nitrate solution, the substrate was sonicated for 30 min, soaked at room temperature for 12 h, and dried. Then, under a nitrogen atmosphere, the substrate was pyrolyzed at 400 °C for 3 h at a heating rate of 5 °C / min to synthesize the product.

[0119] The experimental conditions for controlling catalytic ozone were as follows: initial ozone concentration of 5 mg / L, carbon dosage of 80 mg / L, DEA concentration of 8 μM, temperature of 25℃, use of 3 mM phosphate buffer, and pH adjustment to 6.5 with HClO4 and NaOH.

[0120] like Figure 25 , Figure 26 and Figure 27 As shown, SC loaded with 1 wt% each of bimetallic Ce and Ni 1.5 It has good ozone catalytic activity.

[0121] Example 10:

[0122] This embodiment examines SC. 1.5 and Ce 1wt% - Ni 1wt / SC 1.5 Performance of secondary effluent from municipal wastewater treatment plants. This secondary effluent comes from the end-of-pipe anaerobic-aerobic (AO) and membrane bioreactor (MBR) processes, hereinafter referred to as AO secondary effluent and MBR secondary effluent. Table 2 shows the water quality parameters of the AO and MBR secondary effluents.

[0123] Table 2 Water quality parameters of secondary effluent from municipal wastewater

[0124]

[0125] The experimental conditions for controlling catalytic ozone were as follows: initial ozone concentration of 5 mg / L, carbon dosage of 80 mg / L, DEA concentration of 8 μM, temperature of 25℃, and pH adjusted to 6.5 with HClO4 and NaOH.

[0126] like Figure 28 , Figure 29 and Figure 30 As shown, the addition of SC... 1.5 Or Ce 1wt% - Ni 1wt% / SC 1.5 The catalyst improved the degradation efficiency of DEA.

[0127] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. Use of a black and odorous water sludge-based carbon catalyst in catalytic ozonation, characterized in that, The black and odorous water silt-based carbon catalyst is prepared by the following method, comprising: (1) mixing, drying and grinding the black and odorous water silt and non-silt biomass materials to obtain carbon-increased silt; the weight ratio of the black and odorous water silt to the non-silt biomass material is 1:(0.5-2); (2) after the carbon-increased silt is activated, pyrolysis and cooling are carried out under an inert atmosphere to obtain the black and odorous water silt-based carbon catalyst; through co-pyrolysis of the black and odorous water silt and the non-silt biomass material, the graphitization degree of the carbon-based catalyst can be improved, the graphitization degree is conducive to the electronic transmission capacity of the catalyst, and in the calcination process, part of the heavy metals are coordinated with carbon or nitrogen to form local active sites, thereby strengthening the catalytic activity of the catalyst; After step (2), the black and odorous water silt-based carbon catalyst is loaded with metal oxides by impregnation to obtain a metal-loaded carbon catalyst; the metal in the metal oxide is one or more of Fe, Co, Ni, Mn and Ce; In step (2), the atmosphere for pyrolysis is nitrogen, the temperature is 300-1000℃, the time is 0.5-6 h, and the heating rate is 3-20℃ / min.

2. Use of the black and odorous water sludge-based carbon catalyst according to claim 1 in catalyzing ozone oxidation, characterized in that, In step (1), the carbon-increased silt has a mesh size of 18-200 mesh.

3. Use of the black and odorous water sludge-based carbon catalyst according to claim 1 in catalyzing ozone oxidation, characterized in that, In step (2), the specific steps for activating the carbon-increased silt are as follows: The carbon-increased silt and an activator are mixed in deionized water to prepare a mixed solution, then the mixed solution is immersed at room temperature for 2-72 h, filtered and dried; wherein the activator is at least one of H2SO4, H3PO4 and ZnCl2, or at least one of NaOH, KOH, NaHCO3, Na2CO3, KHCO3 and K2CO3.

4. Use of the black and odorous water sludge-based carbon catalyst according to claim 3 in catalyzing ozone oxidation, characterized in that, In step (2), the mass ratio of the activator to the carbon-increased silt is (0.1-5):

1.

5. Use of the black and odorous water sludge-based carbon catalyst according to claim 4 in catalyzing ozone oxidation, characterized in that, In step (2), the mass ratio of the activator to the carbon-increased silt is (1-2):

1.

6. Use of the black and odorous water sludge-based carbon catalyst according to claim 1 in catalyzing ozone oxidation, characterized in that, The metal content in the metal-loaded carbon catalyst is 0.1%-20 wt %.

7. Use of the black and odorous water sludge-based carbon catalyst according to claim 1 in catalyzing ozone oxidation, characterized in that, After step (2), the black and odorous water silt-based carbon catalyst is pickled, washed with water until the pH is neutral, and dried.

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