Preparation method of reticular iron-carbon filler for strengthening biochemical treatment of coal chemical industry wastewater

Abstract

The application discloses a preparation method of a reticular iron-carbon filler for reinforcing biochemical treatment of coal chemical industry wastewater, and is specifically implemented according to the following steps: step 1, uniformly mixing pure iron powder and activated carbon according to a proportion, and heating under an inert atmosphere; step 2, uniformly mixing the mixture after heating in step 1 with pretreated nano cobalt powder, then adding oxalic acid and ammonium chloride, and uniformly mixing under the inert atmosphere; step 3, placing the mixture in step 2 and a ball milling liquid in a ball mill for treatment for 8h-12h; step 4, taking out the mixture after ball milling, and drying at normal temperature for 24h; step 5, placing the dried mixture in a high-temperature furnace under a nitrogen protection atmosphere for sintering; step 6, immersing the sintered mixture in acid liquid, and stirring in a constant-temperature stirrer; and step 7, reticular molding. The material prepared by the application can effectively improve the performance of a reactor, improve treatment efficiency, and realize efficient treatment of wastewater.

Description

Technical Field

[0001] This invention belongs to the technical field of coal chemical wastewater treatment material preparation methods, specifically relating to a method for preparing a mesh-like iron-carbon packing for enhancing the biochemical treatment of coal chemical wastewater. Background Technology

[0002] Biochemical treatment of coal chemical wastewater is an important area of ​​environmental protection. Its main purpose is to remove organic matter and pollutants such as nitrogen and phenols from the wastewater to meet environmental emission standards. However, many problems exist, such as low treatment efficiency, high investment costs, and high operating expenses. To solve these problems, new treatment technologies and materials need to be sought.

[0003] Iron-carbon packing material, as a novel packing material, possesses a high specific surface area, excellent adsorption and catalytic properties. Its microbiological interaction with organic matter and microorganisms creates a unique microenvironment that significantly accelerates the degradation rate of organic matter and effectively reduces problems such as sediment and odor in subsequent processes, thereby improving the efficiency of biochemical treatment. Furthermore, iron-carbon packing material has relatively low production and maintenance costs, a long service life, is environmentally friendly, and is highly adaptable to different water qualities and temperatures, thus attracting widespread research and application. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a mesh-like iron-carbon packing for enhancing the biochemical treatment of coal chemical wastewater, which can improve the treatment efficiency of coal chemical wastewater.

[0005] The technical solution adopted in this invention is a method for preparing a mesh-like iron-carbon packing for enhancing the biochemical treatment of coal chemical wastewater, specifically implemented according to the following steps:

[0006] Step 1: Mix pure iron powder and activated carbon evenly in a certain proportion and heat under an inert atmosphere;

[0007] Step 2: Mix the heated mixture from Step 1 with the pretreated nano-cobalt powder evenly, then add oxalic acid and ammonium chloride, and mix evenly under an inert atmosphere;

[0008] Step 3: Place the mixture from Step 2 and the ball milling slurry in a ball mill and treat for 8-12 hours;

[0009] Step 4: After ball milling, remove the mixture and dry it at room temperature for 24 hours.

[0010] Step 5: Sinter the dried mixture in a high-temperature furnace under a nitrogen protective atmosphere;

[0011] Step 6: Immerse the sintered mixture in acid solution and stir it in a constant temperature stirrer;

[0012] Step 7: Mesh forming.

[0013] The invention is further characterized by:

[0014] In step 1, the iron powder accounts for 60% to 80% of the total mass, and the activated carbon accounts for 10% to 25% of the total mass.

[0015] After the nano-cobalt powder is mixed with the mixture from step 1, its mass percentage accounts for 5% to 15% of the total mass of the mixture.

[0016] In step 2, oxalic acid is added as a reducing agent and ammonium chloride is added as a nitrogen source. The amount of oxalic acid and ammonium chloride used is 0.5% to 3% of the mass of the mixture.

[0017] In step 3, the ball milling fluid should be either methanol or ethanol.

[0018] In step 5, the sintering temperature is 800℃~1450℃, and the sintering time is 4h~8h.

[0019] The acid solution in step 6 is concentrated nitric acid.

[0020] Step 7 is implemented in the following steps:

[0021] Step 7.1: Mix the polymer powder with an organic solvent to form a paste;

[0022] Step 7.2: Apply the mixture from step 7.1 to the surface of the mesh template and compact it;

[0023] Step 7.3: Spread the prepared iron-carbon material evenly on the mixture in step 7.2, and fix it on the grid template with solvent-based adhesive;

[0024] Step 7.4: Place the mesh template from Step 7.3 into a high-temperature furnace for sintering;

[0025] Step 7.5: Remove the sintered mesh template, clean the dissolved adhesive and template, and then dry it to obtain the final product.

[0026] In step 7.1, the polymer powder is polystyrene or polystyrene copolymer powder, and the organic solvent is either acetone or toluene.

[0027] In step 7.3, the solvent-based adhesive is either an epoxy resin adhesive or an acrylic resin adhesive.

[0028] The beneficial effects of this invention are:

[0029] (1) Improve treatment efficiency: Iron-carbon filler has a high specific surface area and good adsorption performance, which can significantly improve the degradation rate of organic matter in wastewater. The microbiological connection formed between it and microorganisms can create a microenvironment conducive to microbial growth and metabolism, further promoting the efficiency of organic matter degradation and shortening the treatment time.

[0030] (2) Reduced investment costs: Compared with traditional wastewater treatment methods, the use of iron-carbon packing for biochemical treatment reduces the number of required equipment and process units. The production and maintenance costs of the packing are relatively low, and its service life is long, thereby reducing the overall investment cost.

[0031] (3) Save operating costs: Iron-carbon packing has good anti-pollution performance and is not easy to generate sediment, which reduces the frequency of sediment removal and operating costs in subsequent processes. In addition, the packing is highly adaptable and still has good treatment effect under different water quality and temperature, reducing the cost of equipment rework and adjustment due to water quality changes.

[0032] (4) Environmentally friendly and sustainable: No environmental pollutants are generated during the preparation of the filler, and the filler can be recycled and reused, which is in line with the concept of sustainable development. Attached Figure Description

[0033] Figure 1 This is a schematic diagram comparing the effects of adding filler before and after the addition of filler in the biochemical treatment of coal chemical wastewater.

[0034] Figure 2 This is a schematic diagram comparing the effects of adding filler before and after adding filler in the biochemical treatment of coal chemical wastewater. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0036] The present invention relates to a method for preparing a mesh-like iron-carbon packing for enhancing the biochemical treatment of coal chemical wastewater, which is implemented according to the following steps:

[0037] Step 1: Mix pure iron powder and activated carbon evenly in a certain proportion, and heat under an inert atmosphere to remove impurities and moisture;

[0038] In step 1, the iron powder accounts for 60% to 80% of the total mass, and the activated carbon accounts for 10% to 25% of the total mass. If the content of one component increases, the content of other components decreases.

[0039] Step 2: Mix the heated mixture from Step 1 with the pretreated nano-cobalt powder evenly, then add oxalic acid and ammonium chloride, and mix evenly under an inert atmosphere;

[0040] After the nano-cobalt powder is mixed with the mixture from step 1, its mass percentage accounts for 5% to 15% of the total mass of the mixture.

[0041] The pretreatment of nano-cobalt powder includes reduction and drying, which can be achieved through reducing agents and heat treatment;

[0042] In step 2, oxalic acid is added as a reducing agent to reduce iron oxidation and promote the dispersion of dopants. Ammonium chloride is added as a nitrogen source to increase the nitrogen content of the sample and improve catalytic performance. The amount of oxalic acid and ammonium chloride used is 0.5% to 3% of the mass of the mixture.

[0043] Step 3: Place the mixture from Step 2 and the ball milling slurry in a ball mill and process for 8-12 hours until the particle size of the mixture is uniform.

[0044] In step 3, the ball milling fluid should be either methanol or ethanol.

[0045] Step 4: After ball milling, remove the mixture and dry it at room temperature for 24 hours until it is completely dry.

[0046] Step 5: The dried mixture is sintered in a high-temperature furnace under a nitrogen protective atmosphere to form a strong and stable iron-carbon filler.

[0047] In step 5, the sintering temperature is 800℃~1450℃, and the sintering time is 4h~8h;

[0048] Step 6: Etch the sintered mixture by soaking it in acid and stirring it in a constant temperature stirrer until the iron and cobalt elements are fully released and a uniform microstructure is formed.

[0049] The acid solution in step 6 is concentrated nitric acid;

[0050] Step 7: Mesh forming;

[0051] Step 7 is implemented in the following steps:

[0052] Step 7.1: Mix the polymer powder with an organic solvent to form a paste;

[0053] Step 7.2: Apply the mixture from Step 7.1 to the surface of the mesh template and compact it.

[0054] Step 7.3: Spread the prepared iron-carbon filler evenly on the mixture in step 7.2, and fix it on the grid template with solvent-based adhesive;

[0055] Step 7.4: Place the mesh template from step 7.3 in a high-temperature furnace for sintering, so that the iron-carbon filler and polymer powder melt together to form a mesh structure;

[0056] Step 7.5: Remove the sintered mesh template, clean the dissolved adhesive and template, and then dry it to obtain the final product;

[0057] In step 7.1, the polymer powder is polystyrene or polystyrene copolymer powder, and the organic solvent is either acetone or toluene.

[0058] In step 7.3, the solvent-based adhesive is either an epoxy resin adhesive or an acrylic resin adhesive.

[0059] Example 1

[0060] After high-temperature sintering, iron and carbon materials form oxides and other impurities. These oxides and impurities reduce the properties of iron-carbon materials, such as conductivity and corrosion resistance. Therefore, etching treatment is necessary to remove these oxides and impurities. This is typically done by immersion in acid or alkali solutions or by spraying, allowing the oxides and impurities to dissolve or detach. After etching treatment, the physicochemical properties of iron-carbon materials are better preserved, and their service life is also extended.

[0061] The biochemical treatment section of coal chemical wastewater typically uses A / O and A 2 In A / O and A2 / O processes, iron-carbon packing materials are mainly used to provide a fixed mounting area for nitrification and denitrification of biofilms. In the MBR process, iron-carbon packing materials are widely used as passive carriers for biofilm in MBBR reactors, serving as biofilm attachment materials to provide sufficient attachment area, thereby increasing the reactor's processing capacity and stability.

[0062] Example 2

[0063] The preparation method of the mesh iron-carbon packing material for enhancing the biochemical treatment of coal chemical wastewater is carried out according to the following steps:

[0064] Step 1: Weigh a certain amount of pure iron powder and activated carbon, mix them according to the mass ratio of pure iron powder to activated carbon of 8:1, heat to 600℃ under an inert atmosphere to remove impurities and moisture; add 10% of the sample mass of treated nano cobalt powder, 2% of the sample mass of oxalic acid and ammonium chloride, and mix evenly.

[0065] Step 2: Add methanol ball milling slurry. The specific amount of ball milling slurry used depends on various factors such as the size of the ball mill and the properties of the material. The ball milling time is 10 hours until the particle size of the mixture is uniform.

[0066] Step 3: After drying, high-temperature sintering is carried out by heating to 800℃ at a rate of 20℃ / min and holding the temperature for 6 hours. After cooling, the iron-carbon filler is subjected to etch treatment.

[0067] Step 4: Mix the polystyrene copolymer powder with toluene to form a paste, then apply it to the surface of the mesh template and compact it. The iron-carbon filler is evenly spread on the mixture of the mesh template and then bonded to the mesh template with epoxy resin adhesive. The mesh template is placed in a high-temperature furnace for sintering, so that the iron-carbon filler and polymer powder melt together to form a mesh structure. After sintering, the mesh template is removed, the adhesive and template are cleaned and dissolved, and then dried to obtain the mesh iron-carbon filler. Subsequent mesh molding will yield the mesh iron-carbon filler.

[0068] It is applied to the A / O process for the biochemical treatment of coal chemical wastewater, for reference. Figure 1 The change in COD removal rate before and after adding the packing material was shown. The COD removal rate increased by 13.4% after adding the packing material. (Reference) Figure 2 The change in phenolic pollutant removal rate before and after the addition of filler was shown, with the phenolic pollutant removal rate increasing by 21.9%.

[0069] Example 3

[0070] The preparation method of the mesh iron-carbon packing material for enhancing the biochemical treatment of coal chemical wastewater is carried out according to the following steps:

[0071] Step 1: Weigh a certain amount of pure iron powder and activated carbon, mix them according to the mass ratio of pure iron powder to activated carbon of 6:1, heat to 600℃ under an inert atmosphere to remove impurities and moisture; add 15% of the sample mass of treated nano cobalt powder, 3% of the sample mass of oxalic acid and ammonium chloride, and mix evenly.

[0072] Step 2: Add methanol ball milling slurry. The specific amount of ball milling slurry used depends on various factors such as the size of the ball mill and the properties of the material. The ball milling time is 10 hours until the particle size of the mixture is uniform.

[0073] Step 3: After drying, high-temperature sintering is carried out by heating to 1200℃ at a rate of 20℃ / min and holding the temperature for 4 hours. After cooling, the iron-carbon filler is subjected to etch treatment.

[0074] Step 4: Mix the polystyrene copolymer powder with toluene to form a paste, then apply it to the surface of the mesh template and compact it. The iron-carbon filler is evenly spread on the mixture of the mesh template and then bonded to the mesh template with epoxy resin adhesive. The mesh template is placed in a high-temperature furnace for sintering, so that the iron-carbon filler and polymer powder melt together to form a mesh structure. After sintering, the mesh template is removed, the dissolved adhesive and template are cleaned, and then dried to obtain the mesh iron-carbon filler.

[0075] It is applied to the MBR process for the biochemical treatment of coal chemical wastewater, for reference. Figure 1 The change in COD removal rate before and after adding the packing material was shown. The COD removal rate increased by 14.8% after adding the packing material. (Reference) Figure 2The change in phenolic pollutant removal rate before and after the addition of filler was shown, with the phenolic pollutant removal rate increasing by 20.7%.

[0076] The present invention relates to a method for preparing a mesh-like iron-carbon packing for enhancing the biochemical treatment of coal chemical wastewater. The prepared material is applied to denitrification, nitrification, and biofilm immobilization in wastewater treatment processes, effectively improving reactor performance, increasing treatment efficiency, and achieving high-efficiency wastewater treatment.

Claims

1. A method for preparing a reticular iron-carbon filler for strengthening the biochemical treatment of coal chemical wastewater, characterized in that, Specifically, the following steps are implemented: Step 1, uniformly mix pure iron powder and activated carbon in proportion, and heat under inert atmosphere; Step 2, uniformly mix the mixture heated in step 1 with pre-treated nano cobalt powder, then add oxalic acid and ammonium chloride, and mix uniformly under inert atmosphere; Step 3, place the mixture in step 2 and ball milling liquid in a ball mill for 8-12 hours; Step 4, take out the mixture after ball milling and dry at room temperature for 24 hours; Step 5, place the dried mixture in a high temperature furnace under nitrogen protection atmosphere for sintering; Step 6, soak the sintered mixture in acid solution and place in a constant temperature stirrer for stirring; Step 7, mesh forming; The step 7 is implemented according to the following steps: Step 7.1, mix polymer powder and organic solvent to make paste; Step 7.2, apply the mixture in step 7.1 on the surface of the network template and compact; Step 7.3, evenly spread the prepared iron-carbon material on the mixture of step 7.2, and fix it on the grid template with solvent-based adhesive; Step 7.4, place the grid template in step 7.3 in a high temperature furnace for sintering; Step 7.5, take out the sintered grid template, clean and dissolve the glue and template, then dry to obtain; The polymer powder in step 7.1 is polystyrene or polystyrene copolymer powder, and the organic solvent is one of acetone or toluene; The solvent-based adhesive in step 7.3 is one of epoxy resin adhesive or acrylic resin adhesive.

2. The method for preparing the reticular iron-carbon filler for strengthening the biochemical treatment of coal chemical industry wastewater according to claim 1, characterized in that, The mass percentage of iron powder in step 1 is 60%-80% of the total mass, and the mass percentage of activated carbon is 10%-25% of the total mass.

3. The method for preparing the reticular iron-carbon filler for strengthening the biochemical treatment of coal chemical industry wastewater according to claim 1, characterized in that, The mass percentage of nano cobalt powder in step 2 after mixing with the mixture of step 1 is 5%-15% of the total mass after mixing.

4. The method for preparing the reticular iron-carbon filler for strengthening the biochemical treatment of coal chemical industry wastewater according to claim 1, characterized in that, Oxalic acid is added as a reducing agent and ammonium chloride is added as a nitrogen source in step 2, and the usage amount of oxalic acid and ammonium chloride is 0.5%-3% of the mass of the mixture.

5. The method for preparing the reticular iron-carbon filler for strengthening the biochemical treatment of coal chemical industry wastewater according to claim 1, characterized in that, The ball milling liquid in step 3 is one of methanol or ethanol.

6. The method for preparing the reticular iron-carbon filler for strengthening the biochemical treatment of coal chemical industry wastewater according to claim 1, characterized in that, The sintering temperature in step 5 is 800℃-1450℃, and the sintering time is 4-8 hours.

7. The method for preparing the reticular iron-carbon filler for strengthening the biochemical treatment of coal chemical industry wastewater according to claim 1, characterized in that, The acid solution in step 6 is concentrated nitric acid.

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