Preparation method of iron-manganese composite-based porous polyurethane cement sponge filler

Abstract

The application relates to a preparation method of an iron-manganese composite-based porous polyurethane cement sponge filler, and belongs to the technical field of sponge fillers. The method solves the defects of the existing sulfur autotrophic denitrification technology. The required proportions of ordinary Portland cement, anhydrous manganese chloride (MnCl2) and ferrous chloride tetrahydrate (FeCl2.4H2O) are weighed, mixed and stirred uniformly, a water phase solution containing a bonding agent polyvinyl alcohol (PVA) and a dispersant sodium polyacrylate (SPAN) is prepared, solid raw materials and the water phase solution are mixed, polyurethane sponge is added into the mixture and stirred, freezing and shaping are carried out, freezing drying is carried out, steam curing is carried out, then, after being cooled to room temperature, the material is washed with deionized water, and finally, drying treatment is carried out. The iron-manganese composite-based porous polyurethane cement sponge filler has a large specific surface area, porosity, rough surface and good hydrophilicity, and has high phosphorus adsorption and sulfur fixation capacity, thereby exhibiting excellent environmental purification performance and excellent microbial adhesion.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sponge fillers, in particular to a preparation method of an iron-manganese composite-based porous polyurethane cement sponge filler. BACKGROUND

[0002] Water eutrophication is considered as one of the most serious environmental pollution problems in the world, and nitrogen and phosphorus compounds are the main pollution factors leading to water eutrophication. Therefore, the emission standards of nitrogen and phosphorus are also more stringent in China. For example, the emission standards of total nitrogen (TN) and total phosphorus (TP) in Beijing, Shanghai and key lakes such as Dianchi Lake are 5-12 mg / L and 0.05-0.3 mg / L respectively. However, the development trend of low-carbon source of urban sewage in China leads to the fact that the traditional main process is difficult to reduce nitrogen and phosphorus to the relevant emission standards. Therefore, the direct discharge of the secondary effluent of the urban sewage treatment plant is still an important source of excessive nitrogen and phosphorus in the natural aquatic ecosystem. Therefore, it is necessary to carry out deep treatment on the secondary effluent of the sewage plant, which is low-C / N wastewater.

[0003] Currently, in order to achieve the effect of deep denitrification, sewage treatment plants usually add a large amount of organic compounds such as methanol and sodium acetate as carbon source, which not only increases the treatment cost, but also may cause secondary pollution problem. The sulfur autotrophic denitrification technology has obvious advantages in sludge yield and cost because it does not need external carbon source, and is increasingly becoming a new focus in the field of denitrification research, and is therefore widely used in low C / N wastewater treatment. In the sulfur autotrophic denitrification system, in order to support the survival and activity of sulfur autotrophic denitrifying bacteria in the wastewater, specific fillers need to be added to the reactor. These fillers can provide necessary electron donors and inorganic carbon sources. In the conventional sulfur autotrophic denitrification reactor, sulfur is usually used as a sulfur source filler. Although this method is simple and direct, it has some obvious limitations. First, as a single filler, the function of sulfur is relatively single, and the effect of promoting the growth of sulfur autotrophic denitrifying bacteria and accelerating biochemical reaction is not ideal. Secondly, the cost of sulfur is relatively high, which increases the economic burden of the whole process. More importantly, sulfur is a dangerous chemical, and there are certain safety risks in its production, transportation and use. Some researchers use sulfide as a sulfur source. Sulfide is outstanding because of its wide source, good stability, low cost, wide applicability and environmental friendliness, and is considered as the most efficient electron donor in the sulfur autotrophic denitrification process. However, hydrogen sulfide gas may be produced during the denitrification process. Moreover, during the hydrolysis process, hydrogen sulfide gas is also produced, which emits a foul odor and is toxic. Therefore, when conducting innovation and improvement research on sulfur autotrophic denitrification process, we must consider how to improve the multifunctionality and efficiency of the filler. The present application proposes a new type of sulfur autotrophic denitrification filler preparation to solve the above problems of sulfur autotrophic denitrification technology, and constructs a "zero-carbon" denitrification and phosphorus removal biological filter to deeply treat the secondary effluent of municipal sewage treatment plant.

[0004] At present, the porous polyurethane filler using polyurethane as raw material has quite large specific surface area, rough surface, high porosity of up to 97% and good adhesion to microorganisms, and is therefore considered as an ideal carrier for the growth of biofilm. However, the polyurethane sponge in water treatment technology mainly utilizes its unique physical structure without other functions, and the biofilm formed by polyurethane is prone to be washed out due to poor hydrophilicity and is at risk of being damaged. Therefore, the present research proposes to modify polyurethane by using cement doped with manganese and iron to improve the hydrophilicity of polyurethane and endow the polyurethane filler with the functions of sulfur fixation and phosphorus removal.

[0005] To solve the above problems, a preparation method of iron-manganese composite-based porous polyurethane cement sponge filler is proposed. SUMMARY

[0006] The present application aims to provide a preparation method of iron-manganese composite-based porous polyurethane cement sponge filler, which solves the problems in the background art.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a preparation method of iron-manganese composite-based porous polyurethane cement sponge filler, comprising the following steps:

[0008] Step one: accurately weigh the required proportion of ordinary Portland cement, anhydrous manganese chloride (MnCl2) and ferrous chloride tetrahydrate (FeCl2·4H2O) using a precision balance.

[0009] Step two: put the weighed Portland cement, anhydrous manganese chloride and ferrous chloride tetrahydrate into a large-capacity beaker and stir to ensure that the raw materials are fully mixed.

[0010] Step three: in another clean container, add deionized water and polyvinyl alcohol (PVA), heat and stir until it is completely dissolved, and transfer it to a large-capacity bottle, add sodium polyacrylate (SPAN) solution to constant volume, and obtain the prepared aqueous solution.

[0011] Step four: mix the solid raw materials in step two and the aqueous solution in step three thoroughly, add polyurethane sponge to the mixture, continue to stir to ensure that the sponge can fully absorb the slurry.

[0012] Step five: put the material in step four into a freezer to freeze and shape.

[0013] Step six: take out the material in step five and put it into a freeze dryer, and freeze-dry the polyurethane sponge through the vacuum sublimation process of the freeze dryer.

[0014] Step seven: take out the material in step six and place it in a high-pressure steam boiler for steam curing.

[0015] Step eight: take out the material in step seven and place it on a clean workbench for cooling. After cooling to room temperature, gently rinse the material with deionized water, and after cleaning, place the material in an oven for final drying treatment.

[0016] Further, the specific ratio of raw materials and aqueous solution in the preparation of step two and step three is that 10 g of ordinary Portland cement, 0.61 g of anhydrous manganese chloride (MnCl2) and 0.94 g of ferrous chloride tetrahydrate (FeCl2·4H2O) are prepared in five parts respectively, and these raw materials are mixed in five large beakers respectively, then 16 mL, 24 mL, 32 mL, 40 mL and 48 mL of pre-configured aqueous solution containing 1% polyvinyl alcohol (PVA) and 1% sodium polyacrylate (SPAN) are added to each beaker according to the established water-cement ratio (0.8:1, 1.2:1:1, 1.6:1, 2:1, 2.4:1) respectively, and the mixture is fully stirred to form a uniform slurry.

[0017] Further, the specific ratio of raw materials and aqueous solution in the preparation of step two and step three is that 10 g of ordinary Portland cement, 0.61 g of anhydrous manganese chloride (MnCl2) and 0.94 g of ferrous chloride tetrahydrate (FeCl2·4H2O) are prepared in five parts respectively, and these raw materials are mixed in five large beakers respectively, then 16 mL, 24 mL, 32 mL, 40 mL and 48 mL of pre-configured aqueous solution containing 1% polyvinyl alcohol (PVA) and 1% sodium polyacrylate (SPAN) are added to each beaker according to the established water-cement ratio (0.8:1, 1.2:1:1, 1.6:1, 2:1, 2.4:1) respectively, and the mixture is fully stirred to form a uniform slurry.

[0018] Further, the specific ratio of raw materials and aqueous solution in the preparation of step two and step three is that 10 g of ordinary Portland cement, 0.61 g of anhydrous manganese chloride (MnCl2) and 0.94 g of ferrous chloride tetrahydrate (FeCl2·4H2O) are prepared in five parts respectively, and these raw materials are mixed in five large beakers respectively, then 16 mL, 24 mL, 32 mL, 40 mL and 48 mL of pre-configured aqueous solution containing 1% polyvinyl alcohol (PVA) and 1% sodium polyacrylate (SPAN) are added to each beaker according to the established water-cement ratio (0.8:1, 1.2:1:1, 1.6:1, 2:1, 2.4:1) respectively, and the mixture is fully stirred to form a uniform slurry.

[0019] Further, all the chemicals in the step are of analytical purity and are stored in a sealed dry environment.

[0020] Further, the size of the polyurethane sponge in step four is 10 mm*10 mm*10 mm.

[0021] Further, the temperature of the freezing refrigerator in the step five is set to -60 DEG C in advance, and the freezing time of the shaping is 0.5 h.

[0022] Further, the air pressure of the freeze dryer in the step six is set to 0.5-3 pa, and the time is set to 24 h.

[0023] Further, the time of the high-pressure steam in the step seven is 48 h.

[0024] Further, the temperature of the drying in the step eight is set to 95 DEG C, and the time is set to 4 h.

[0025] Compared with the prior art, the present application has the beneficial effects that:

[0026] 1. The present application provides a preparation method of the iron-manganese composite-based porous polyurethane cement sponge filler, and the porosity of the material in the present application is as high as 80%-62%, and the specific surface area reaches 43.1402 m 2 / g. It can be seen from the electron microscope scanning that the filler has high roughness, which is one of the key factors for high-efficiency adsorption. The rough surface provides more adsorption sites for pollutants, increases the contact opportunity between the pollutants and the filler, and improves the adhesion of the filler to microorganisms.

[0027] 2. The adsorption capacity of the filler to phosphorus is as high as 5.4 mg / g, which shows that it has a significant effect on removing phosphorus pollution in water bodies. The sulfur fixation capacity of the filler is as high as 6.75 mg / g. Sulfur exists in various forms in water bodies, and some forms of sulfur have potential risks to the environment and organisms. The high sulfur fixation capacity of the filler means that it can effectively convert these harmful forms of sulfur into harmless or low-harm forms, thereby reducing the impact on the environment. At the same time, the fixed sulfide can be used as an electron donor to construct a "zero-carbon" denitrification and phosphorus removal biological filter. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The preparation flowchart of the iron-manganese composite-based porous polyurethane cement sponge filler of the present application is shown in the figure.

[0029] Figure 2 The porosity and sulfur fixation and phosphorus removal data of the filler obtained in Example One of the present application are shown in the figure.

[0030] Figure 3 The porosity and sulfur fixation and phosphorus removal data of the filler obtained in Example Two of the present application are shown in the figure.

[0031] Figure 4 The porosity and sulfur fixation and phosphorus removal data of the filler obtained in Example Three of the present application are shown in the figure.

[0032] Figure 5This is a sample image of the fourth type of denitrification packing material in Embodiment 3 of the present invention;

[0033] Figure 6 This is a scanning electron microscope image of the fourth type of denitrification packing material in Embodiment 3 of the present invention;

[0034] Figure 7 This is a schematic diagram of the fourth type of denitrification packing material, BET, in Embodiment 3 of the present invention;

[0035] Figure 8 This is a schematic diagram showing the removal rates of sulfur and phosphorus of different concentrations using the fourth type of denitrification packing material in Example 3 of the present invention;

[0036] Figure 9 This is a quasi-first- and second-order kinetic fit of the fourth type of denitrification packing material in Example 3 of the present invention;

[0037] Figure 10 This is a physical image of the packed film reactor in Embodiment 4 of the present invention;

[0038] Figure 11 The figure shows specific data on the degradation of nitrate nitrogen by the three fillers in Example 4 of this invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] To address the existing technical problems, the following will combine... Figures 1-11 The present invention will be described in detail below:

[0041] Example 1:

[0042] The precise balance is used to accurately weigh 10 g of ordinary Portland cement, 0.61 g of anhydrous manganese chloride (MnCl2) and 0.94 g of ferrous chloride tetrahydrate (FeCl2·4H2O) five times, and these raw materials are respectively put into five large beakers, ensuring that the stirring speed is uniform, then, according to the established water-cement ratio (0.8:1, 1.2:1:1, 1.6:1, 2:1, 2.4:1), 16 mL, 24 mL, 32 mL, 40 mL, 48 mL of pre-configured water solution containing 1% polyvinyl alcohol (PVA) and 1% sodium polyacrylate (SPAN) are respectively added to each beaker, and the raw materials are fully stirred to ensure that they are fully mixed to form a uniform slurry, then, 25 10mm x 10mm x 10mm polyurethane sponge blocks are added to the slurry one by one, and continue to stir to ensure that the sponge blocks are evenly dispersed and fully soaked in the slurry, the addition of polyurethane sponge will provide additional physical support for the mixture and play a key role in the subsequent reaction, then, the saturated polyurethane sponge blocks are transferred to a freezer refrigerator at -60℃ for 0.5 hours of freezing shaping treatment, this step is a very critical link in the entire preparation process, because it is directly related to the final physical form and structure of the polyurethane sponge, under the action of low temperature, the water and other solvents in the polyurethane sponge will quickly crystallize and freeze into a solid state, this process will cause the volume of the polyurethane sponge to expand, forming many tiny ice crystals, which will form uniformly distributed pores in the internal structure of the polyurethane sponge, thereby giving the polyurethane sponge its unique porous structure, then, the shaped polyurethane sponge blocks are placed in a freeze dryer, the gas pressure is set to 0.5-3 pa, and the freeze-drying time is maintained for 24 hours to complete the complete removal of water, through the vacuum sublimation process of the freeze dryer, a complex and uniform pore structure is formed inside the polyurethane sponge, these pores are cavities left by the sublimation of water, which run through the entire sponge body, providing the sponge with a large surface area and low density characteristics, after freeze-drying is completed, the polyurethane sponge blocks are taken out and placed in a high-pressure steam boiler for 48 hours of steam curing to promote the full reaction of chemical substances and the stability of the structure, during this stage, water vapor will penetrate into the pores of the material and react with the unreacted chemical substances, after steam curing, the filler is taken out and carefully washed with deionized water to remove possible surface impurities or unreacted chemical substances, after washing, the material is placed in an oven for final drying treatment, the drying temperature is set to 95℃, and the time is 4 hours until the material is completely dried, after the above fine preparation process, the iron-manganese composite-based porous polyurethane cement sponge filler is successfully obtained.

[0043] Example two:

[0044] The precision balance was used to accurately weigh 10 g of ordinary Portland cement, 20 mL of pre-configured water solution containing 1% polyvinyl alcohol (PVA) and 1% sodium polyacrylate (SPAN) five times, and was respectively loaded into five large beakers, according to the established iron manganese doping mass ratio (0%, 5%, 10%, 15%, 20%) to five beakers respectively add anhydrous manganese chloride (MnCl2) 0 g, 0.61 g, 1.27 g, 2.01 g, 2.86 g, ferrous chloride (FeCl2·4H2O) 0 g, 0.94 g, 1.97 g, 3.12 g, 4.44 g, wherein the mass ratio of iron and manganese is 1:1, then, 25 10mm×10mm×10mm polyurethane sponge blocks were added to the slurry one by one, and stirring was continued to ensure that the sponge blocks were uniformly dispersed and fully infiltrated in the slurry. The addition of polyurethane sponge provides additional physical support for the mixture and plays a key role in subsequent reactions. Then, the saturated polyurethane sponge blocks were transferred to a freezer at-60℃ for 0.5 hours of freezing shaping treatment. This step is a very critical link in the entire preparation process, because it is directly related to the final physical form and structure of the polyurethane sponge. Under the action of low temperature, the water and other solvents in the polyurethane sponge will quickly crystallize and freeze into a solid state. This process will cause the volume of the polyurethane sponge to expand, forming many tiny ice crystals. These ice crystals will form uniformly distributed pores in the internal structure of the polyurethane sponge, thereby giving the polyurethane sponge its unique porous structure. After that, the shaped polyurethane sponge blocks were placed in a freeze dryer, the gas pressure was set between 0.5-3 pa, and the freeze-drying time was maintained for 24 hours to completely remove the water. Through the vacuum sublimation process of the freeze dryer, a complex and uniform pore structure is formed inside the polyurethane sponge. These pores are cavities left by the sublimation of water, which run through the entire sponge body, providing a large surface area and low density characteristics for the sponge. After freeze-drying is completed, the polyurethane sponge blocks are taken out and placed in a high-pressure steam boiler for 48 hours of steam curing to promote the full reaction of chemical substances and the stability of the structure. During this stage, water vapor penetrates into the pores of the material and reacts with the unreacted chemical substances. After steam curing, the filler is taken out and rinsed with deionized water to remove any impurities or unreacted chemicals that may be present on the surface. After rinsing, the material is placed in an oven for final drying. The drying temperature is set to 95℃, and the time is 4 hours until the material is completely dry. After the above fine preparation process, the iron-manganese composite-based porous polyurethane cement sponge filler is successfully obtained.

[0045] Example three:

[0046] A precision balance was used to accurately weigh 10 g of ordinary Portland cement, 20 mL of pre-configured water solution containing 1% polyvinyl alcohol (PVA) and 1% sodium polyacrylate (SPAN) each five times, and was loaded into five large beakers, according to the established manganese-iron mass ratio (0%, 20%, 40%, 60%, 100%) to five beakers respectively added anhydrous manganese chloride (MnCl2) 0.243 g, 0.486 g, 0.728 g, 0.97 g, 1.21 g, ferrous chloride tetrahydrate (FeCl2·4H2O) 1.88 g, 1.51 g, 1.13 g, 0.75 g, 0.376 g, wherein the iron manganese doping mass ratio is 5%, then, 25 10 mm x 10 mm x 10 mm polyurethane sponge blocks were added one by one into the slurry, and stirring was continued to ensure that the sponge blocks were uniformly dispersed and fully immersed in the slurry. The addition of polyurethane sponge provided additional physical support for the mixture and played a key role in subsequent reactions. Then, the saturated polyurethane sponge blocks were transferred to a -60°C freezer for 0.5 hours of freezing shaping treatment. This step was a critical link in the entire preparation process, as it directly related to the final physical form and structure of the polyurethane sponge. Under the action of low temperature, the water and other solvents in the polyurethane sponge would quickly crystallize and freeze into a solid state. This process would cause the volume of the polyurethane sponge to expand, forming many tiny ice crystals that would form uniformly distributed pores in the internal structure of the polyurethane sponge, thus giving the polyurethane sponge its unique porous structure. After that, the shaped polyurethane sponge blocks were placed in a freeze dryer, with the gas pressure set between 0.5 and 3 pa, and the freeze-drying time maintained for 24 hours to complete the removal of water. Through the vacuum sublimation process of the freeze dryer, a complex and uniform pore structure was formed inside the polyurethane sponge. These pores were cavities left by the sublimation of water, which ran through the entire sponge body, providing the sponge with a large surface area and low density characteristics. After freeze-drying was completed, the polyurethane sponge blocks were removed and placed in a high-pressure steam boiler for 48 hours of steam curing to promote the full reaction of the chemical substances and the stability of the structure. During this stage, water vapor would penetrate into the pores of the material and react with the unreacted chemical substances. After steam curing, the filler was removed and rinsed with deionized water to remove any surface impurities or unreacted chemicals. After rinsing, the material was placed in an oven for final drying at a temperature of 95°C for 4 hours until the material was completely dry. After the above meticulous preparation process, the iron-manganese composite-based porous polyurethane cement sponge filler was successfully obtained.

[0047] The polyurethane sponge size is 10mm*10mm*10mm cube, which is used to create a larger specific surface area, porosity, rough surface and good adhesion to the microorganisms in the invention, which is conducive to the growth of microorganisms. The silicate cement is a common ordinary Portland cement, which releases calcium ions in water during the hydration process, and the calcium ions combine with the phosphate in water to remove phosphorus. At the same time, the product after hydration of the silicate cement can improve the hydrophilicity of the polyurethane, thereby improving the adhesion of the filler to the microorganisms. The anhydrous manganese chloride and ferrous chloride are the main components for sulfur fixation in the invention. The binder is polyvinyl alcohol (PVA), which can improve the viscosity of the cement slurry and increase the toughness and durability of the final product. The dispersing agent is sodium polyacrylate (SPAN), which can make the cement slurry evenly spread, prevent the cement slurry from settling and coagulating, and also help to adjust the pH value and reduce the surface tension of water, making it easier to combine with inorganic substances.

[0048] Example four:

[0049] The fourth filler in case three is used, and at the same time, the polyurethane sponge is compared with the cement polyurethane sponge without iron and manganese. The three fillers are connected in series by a water line with a diameter of 0.2mm, and are hung in the reactor. Figure 10 The effective volume of the device is 1.7 liters, the filling rate of the filler is 67%, and the sludge concentration is 5g / L. Before the device starts running, we inject a solution of sodium sulfide (Na2S·9H2O) with a concentration of 0.975g / L into it to ensure that the filler fully absorbs sulfur. Subsequently, a continuous flow of water is used, and the concentration of NO3 - -N in the water is controlled at 20mg / L, the concentration of PO4 3- -P is 1mg / L, and the water temperature is maintained at 25 degrees Celsius, and the pH value is controlled between 7-8. During the experiment, water samples are collected regularly, and key indicators such as nitrate nitrogen and sulfate in the effluent are analyzed. After the biofilm is stable, we evaluate the activity of the biofilm on the three fillers. Specifically, we take 20 of each filler from the reactor, wash the surface with deionized water, and then put them into 50mL centrifuge tubes, and add 30mL of mixed solution containing NO3 - -N:40mg / L, PO4 3- -P:1mg / L, NaS2O3·5H2O:0.775mg / L to each tube. The change of nitrate nitrogen concentration in the system is as follows: Figure 11As shown, it can be seen that the biofilm activity on the iron-manganese composite-based porous polyurethane cement sponge filler is obviously stronger than that on the pure polyurethane sponge and the cement polyurethane sponge without iron and manganese.

[0050] It should be noted that, in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0051] The above description is merely preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical range disclosed in the present application and the inventive concept, can make equivalent replacements or changes within the technical range, and all of them should be covered within the protection scope of the present application.

Claims

1. A process for the preparation of ferromanganese composite based porous polyurethane cement sponge filler, characterized by, The method comprises the following steps: Step one: accurately weigh the required proportion of ordinary Portland cement, anhydrous manganese chloride and ferrous chloride tetrahydrate using a precision balance; Step two: place the weighed Portland cement, anhydrous manganese chloride and ferrous chloride tetrahydrate into a large-capacity beaker and stir to ensure that the raw materials are fully mixed; Step three: in another clean container, add deionized water and polyvinyl alcohol, heat and stir until it is completely dissolved, and then transfer it to a large-capacity bottle, add a sodium polyacrylate solution to make up the volume, and obtain a prepared aqueous solution containing 1% polyvinyl alcohol and 1% sodium polyacrylate; Step four: mix the solid raw materials in step two and the aqueous solution in step three thoroughly, add polyurethane sponge to the mixture, and continue stirring to ensure that the sponge can fully absorb the slurry; Step five: place the material obtained in step four in a freezer to freeze and shape; Step six: take out the material obtained in step five and place it in a freeze dryer, and freeze-dry the polyurethane sponge through the vacuum sublimation process of the freeze dryer; Step seven: take out the material obtained in step six and place it in a high-pressure steam boiler for steam curing; Step eight: take out the material obtained in step seven and place it on a clean workbench for cooling; after cooling to room temperature, gently rinse the material with deionized water, and after cleaning, place the material in an oven for final drying treatment; The optimal preparation parameters of the method are: water-cement ratio of 2:1, iron-manganese doping mass ratio of 5%, and manganese-iron mass ratio of 0.

8.

2. A process for the preparation of a ferromanganese composite based porous polyurethane cement sponge filler as claimed in claim 1, wherein: All chemical reagents in the steps are of analytical purity and are stored in a sealed dry environment.

3. A process for the preparation of ferromanganese composite based porous polyurethane cement sponge filler as claimed in claim 1, wherein: The size of the polyurethane sponge in step four is 10mm*10mm*10mm.

4. A process for the preparation of ferromanganese composite based porous polyurethane cement sponge filler as claimed in claim 1, wherein: The temperature of the freezer in step five is set to -60°C in advance, and the freezing and shaping time is 0.5h.

5. A process for the preparation of ferromanganese composite based porous polyurethane cement sponge filler as claimed in claim 1, wherein: The gas pressure of the freeze dryer in step six is set to 0.5~3Pa, and the time is set to 24h.

6. A process for the preparation of ferromanganese composite based porous polyurethane cement sponge filler as claimed in claim 1, wherein: The high-pressure steam time in step seven is 48h.

7. A process for the preparation of ferromanganese composite based porous polyurethane cement sponge filler as claimed in claim 1, wherein: The drying temperature in step eight is set to 95°C, and the time is set to 4h.

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