Preparation method and application of rare earth modified biological carrier for enhancing MBBR denitrification

Abstract

The present invention belongs to the technical field of sewage treatment, and in particular, relates to a preparation method and application of a rare earth modified biological carrier for strengthening MBBR denitrification, and more specifically to a preparation method and application of a rare earth modified biological carrier for accelerating biofilm formation and strengthening MBBR denitrification performance. The present invention uses polyurethane sponge as a skeleton, polyvinyl alcohol and lanthanum oxide as fillers to prepare a rare earth modified biological carrier, which can effectively accelerate biofilm formation, improve MBBR denitrification and other pollutant treatment effects when used as a filler in an MBBR process. The biological carrier has good corrosion resistance in water as a composite filler, high film-forming efficiency, long service life, and significant MBBR denitrification effect, good biological affinity, convenient recycling, and a simple preparation method.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a preparation method and application of a rare earth modified biological carrier for strengthening MBBR denitrification. Background Art

[0002] Most of the existing sewage treatment plants use the biofilm method, which is widely used in the removal of organic matter and denitrification of sewage due to its high efficiency and low operating cost. The use of the biofilm process for wastewater denitrification has a positive effect on alleviating the current problems of eutrophication of water bodies and land shortage for wastewater treatment facilities, and has great development potential. One of the key elements of MBBR is the biofilm carrier. Polyurethane sponge is selected because of its high mechanical strength, large specific surface area, rough surface and good adhesion to microorganisms. In addition, another advantage of polyurethane sponge is that there is a high dissolved oxygen (DO) gradient in the cubic biofilm. However, they also have some disadvantages, including low hydrophilicity of the filler, high possibility of biofilm shedding, and unstable microenvironment, so it is expected that new methods will be found to improve the performance of polyurethane sponge, such as modification (hydrophilicity or charge) or combination with other carriers.

[0003] With the continuous improvement of sewage treatment requirements and the development of MBBR technology, the market demand for high-performance biological fillers is increasing. In order to meet market demand, improve sewage treatment efficiency, explore the feasibility of combining rare earths with biological carriers, and conduct in-depth research on innovative combinations of rare earth materials and biological carriers, it is necessary to develop a new type of rare earth modified biological carrier. Its modified core element - lanthanum, the introduction of lanthanum can not only promote the efficient attachment and rapid growth of microorganisms on the carrier surface, but also significantly enhance the formation and structural stability of biofilms, accelerate the biofilm process, and greatly improve the efficiency of biological treatment systems. The new rare earth modified biological carrier has lower operating costs and higher treatment efficiency, achieving a win-win situation of economic and social benefits, and contributing new solutions and technical strategies to the effective treatment of domestic sewage. Summary of the invention

[0004] The purpose of the present invention is to provide a preparation method and application of a rare earth modified biological carrier for enhanced MBBR denitrification. Conventional polyurethane block sponge filler is modified by using lanthanum oxide and polyvinyl alcohol. A certain amount of lanthanum oxide is attached to the surface of the modified sponge filler. When used for sewage treatment, the enhanced MBBR denitrification and other pollutant treatment effects can be improved. The biological carrier as a composite filler has good corrosion resistance in water, long service life, significant enhanced MBBR denitrification effect, good biological affinity, convenient recycling, and a simple preparation method.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is to provide a rare earth modified bio-carrier for strengthening MBBR denitrification, wherein the rare earth modified bio-carrier for strengthening MBBR denitrification has a polyurethane sponge as a skeleton and polyvinyl alcohol and lanthanum oxide as fillers.

[0007] Further, the usage ratio of the polyurethane sponge, polyvinyl alcohol and lanthanum oxide is 405cm 3 :5g:15g.

[0008] The second technical solution of the present invention is to provide a method for preparing the rare earth modified biological carrier for enhancing MBBR denitrification, the steps comprising:

[0009] Mixing polyvinyl alcohol and water, and stirring at a constant temperature until the polyvinyl alcohol is completely dissolved, to obtain a polyvinyl alcohol aqueous solution;

[0010] Dispersing lanthanum oxide evenly in a polyvinyl alcohol solution to obtain a filler solution;

[0011] The polyurethane sponge is immersed in the filler solution, stirred by magnetic force, and then dried to obtain the enhanced MBBR denitrification rare earth modified bio-carrier.

[0012] Furthermore, the mass ratio of the polyvinyl alcohol to water is 5:100.

[0013] Furthermore, the temperature of the constant temperature stirring is 120° C. and the rotation speed is 100 rpm.

[0014] Furthermore, the magnetic stirring time is 30 min.

[0015] Furthermore, the drying temperature is 100°C.

[0016] The third technical solution of the present invention is to provide an application of the above-mentioned rare earth modified biological carrier for enhanced MBBR denitrification as a filler in the MBBR process.

[0017] Technical solution 4 of the present invention: Provide a method for improving the denitrification effect of MBBR process filler MBBR, the steps comprising:

[0018] Mixing polyvinyl alcohol and water, and stirring at a constant temperature until the polyvinyl alcohol is completely dissolved, to obtain a polyvinyl alcohol aqueous solution;

[0019] Dispersing lanthanum oxide evenly in a polyvinyl alcohol solution to obtain a filler solution;

[0020] The polyurethane sponge is immersed in the filler solution, stirred by magnetic force, and then dried to obtain a rare earth modified bio-carrier for enhanced MBBR denitrification;

[0021] The rare earth modified bio-carrier for enhancing MBBR denitrification is used as a filler in the MBBR process.

[0022] Technical solution 5 of the present invention: Provide a method for improving the biofilm formation speed and effect of MBBR process fillers, the steps comprising:

[0023] Mixing polyvinyl alcohol and water, and stirring at a constant temperature until the polyvinyl alcohol is completely dissolved, to obtain a polyvinyl alcohol aqueous solution;

[0024] Dispersing lanthanum oxide evenly in a polyvinyl alcohol solution to obtain a filler solution;

[0025] The polyurethane sponge is immersed in the filler solution, stirred by magnetic force, and then dried to obtain a rare earth modified bio-carrier for enhanced MBBR denitrification;

[0026] The rare earth modified bio-carrier for enhancing MBBR denitrification is used as a filler in the MBBR process.

[0027] Polyurethane sponge belongs to organic polymer filler, and its porous and transparent structure greatly increases the specific surface area of ​​the product, which is conducive to the large-scale reproduction of microorganisms. It is a commonly used biological carrier in the current MBBR process; the innovative combination of traditional polyurethane sponge and rare earth materials, the introduction of lanthanum elements can not only promote the efficient attachment and rapid growth of microorganisms on the carrier surface, but also promote the densification and stability enhancement of the biofilm structure, accelerate the biofilm process, and greatly improve the effectiveness and efficiency of the biological treatment system. The new rare earth lanthanum modified biological carrier has lower operating costs and higher treatment efficiency, achieving a win-win situation of economic benefits and social benefits, and opening up a new way to improve the comprehensive performance of the sewage treatment system. Polyvinyl alcohol has good biocompatibility and is also a good adhesive. Therefore, in order to avoid introducing other chemical substances, the preparation of the lanthanum oxide modified polyurethane sponge filler of the present invention is selected to be synthesized as a modifier by rare earth metal lanthanum oxide and polyvinyl alcohol, and the polyurethane sponge is immersed in a filler solution, and a lanthanum oxide modified polyurethane sponge filler that can be used for MBBR process MBBR denitrification and improve biofilm rate is obtained after drying.

[0028] The present invention discloses the following technical effects:

[0029] The invention uses polyurethane sponge as a skeleton, polyvinyl alcohol and lanthanum oxide as fillers to prepare a rare earth modified biological carrier for strengthening MBBR denitrification. The introduction of lanthanum elements can not only promote the efficient attachment and rapid growth of microorganisms on the surface of the carrier, but also promote the densification and stability enhancement of the biofilm structure, accelerate the biofilm process, greatly improve the effectiveness and efficiency of the biological treatment system, and greatly improve the nitrogen removal effect during sewage treatment. In addition, the hydrogen bonds formed between the hydroxyl groups of polyvinyl alcohol and other substances are quite strong, so that the rare earth lanthanum oxide can remain attached to the sponge filler for a long time, and a large amount of organic matter is attached to the surface of the sponge filler. The prepared polyvinyl alcohol aqueous solution also has high water resistance.

[0030] The combination of rare earth lanthanum oxide and polyurethane sponge in the present invention increases the density of the product carrier, avoids the disadvantage that the traditional polyurethane sponge easily floats on the water surface, resulting in poor sewage treatment effect. By increasing the density of the product carrier, it can be fully moved in the reactor, improve the mass transfer effect, and be beneficial to the adsorption and degradation of pollutants by microorganisms. Compared with the traditional reactor with a single polyurethane sponge as filler, the biomass is increased by 1.25g / g, and the MBBR denitrification efficiency is increased by 10%.

[0031] The present invention disperses rare earth in a polyvinyl alcohol solution so that the rare earth can enter the gaps in the polyurethane sponge, fully utilizing the porous structure of the sponge, further increasing the specific surface area of ​​the product, facilitating the attachment of microorganisms, and further increasing the attached biomass, thereby improving the biofilm formation speed and effect.

[0032] The process for preparing the biological carrier of the present invention is simple, does not introduce excessive chemical substances, has low cost, is easy to apply, and does not cause secondary pollution to water sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 This is a physical picture of the rare earth modified bio-carrier for enhanced MBBR denitrification prepared in Example 1;

[0035] Figure 2 This is the energy spectrum of the rare earth modified bio-carrier for enhanced MBBR denitrification prepared in Example 1;

[0036] Figure 3 The SEM images of the rare earth modified bio-carrier for enhanced MBBR denitrification prepared in Example 1, wherein (a) is a SEM image of the rare earth modified carrier magnified 30 times, and (b) is a SEM image of the rare earth modified carrier magnified 2000 times;

[0037] Figure 4 The SEM images of common biological carriers, wherein (a) is a SEM image of a common carrier magnified 30 times, and (b) is a SEM image of a common carrier magnified 2000 times;

[0038] Figure 5 Comparative photos of wastewater treated with the biological carriers prepared in Example 1 (left) and Comparative Example 1 (right) as fillers;

[0039] Figure 6The weight change of the bio-carriers prepared in Example 1 and Comparative Example 1 when used as fillers in the MBBR process;

[0040] Figure 7 The ammonia nitrogen concentration and ammonia nitrogen removal rate when the bio-carriers prepared in Example 1 and Comparative Example 1 are used as fillers in the MBBR process, wherein (a) is the ammonia nitrogen concentration and (b) is the ammonia nitrogen removal rate;

[0041] Figure 8 COD when the bio-carriers prepared in Example 1 and Comparative Example 1 are used as fillers in MBBR process Cr Concentration and COD Cr Removal rate, where (a) is COD Cr concentration, (b) is COD Cr Removal rate;

[0042] Fig. 9 It is a MBBR device. DETAILED DESCRIPTION

[0043] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0044] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0045] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0046] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0047] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0048] The raw materials used in the specific embodiment of the present invention are all commercially available products, among which the polyurethane sponge is provided by Yuanshengxing Electronics Co., Ltd., with a product density of 10ppi; lanthanum oxide is provided by Shanghai MacLean Biochemical Technology Co., Ltd.; polyvinyl alcohol is provided by Sinopharm Chemical Reagent Co., Ltd. The volume of a single filler is 9cm 3 The cost of ordinary fillers is about 0.15 yuan, the cost of rare earth modified carriers is about 0.22 yuan, and the volume of a single batch of rare earth modified fillers is 405cm 3 The cost is about 10 yuan.

[0049] Example 1

[0050] The preparation steps of rare earth modified bio-carrier for enhanced MBBR denitrification are as follows:

[0051] S1. Mix 5 g of polyvinyl alcohol and 100 mL of water in a constant temperature water bath at 120° C. and stir (100 rpm) for 2 h until the polyvinyl alcohol is completely dissolved to obtain a polyvinyl alcohol aqueous solution;

[0052] S2, lowering the temperature of the polyvinyl alcohol aqueous solution to 25°C, continuing to stir, and when stirring until there are at least a few bubbles, adding 15g of rare earth lanthanum oxide to the polyvinyl alcohol aqueous solution and dispersing it evenly to obtain a filler solution;

[0053] S3, the volume is 405cm 3 The polyurethane sponge was mixed with the filler solution, immersed and magnetically stirred for 30 minutes and then dried at 100°C for 12 hours. After drying, the incompletely fixed lanthanum oxide on its surface was repeatedly washed off in ultrapure water and dried again (100°C, 12 hours). After naturally cooling to 25°C, an enhanced MBBR denitrification rare earth modified bio-carrier was obtained.

[0054] Figure 1 This is a physical picture of the rare earth modified bio-carrier for enhanced MBBR denitrification prepared in Example 1.

[0055] Figure 2 This is the energy spectrum of the rare earth modified bio-carrier for enhanced MBBR denitrification prepared in Example 1. It can be seen from the figure that the lanthanum element is successfully loaded.

[0056] Comparative Example 1

[0057] The steps for preparing the bio-carrier are:

[0058] S1. Mix 5 g of polyvinyl alcohol and 100 mL of water in a constant temperature water bath at 120° C. and stir (100 rpm) for 2 h until the polyvinyl alcohol is completely dissolved to obtain a polyvinyl alcohol aqueous solution;

[0059] S2, the volume is 405cm 3 The polyurethane sponge was mixed with the polyvinyl alcohol aqueous solution, magnetically stirred for 30 minutes, and then dried (100° C., 12 hours) to obtain a biological carrier.

[0060] Comparative Example 2

[0061] The steps for preparing the bio-carrier are:

[0062] S1. Mix 15 g of rare earth lanthanum oxide and 100 mL of water in a constant temperature water bath at 120° C. and disperse them evenly to obtain a filler solution;

[0063] S2, the volume is 405cm 3 The polyurethane sponge was mixed with the filler solution, magnetically stirred for 30 min, and then dried (100° C., 12 h) to obtain a biological carrier.

[0064] Comparative Example 3

[0065] The steps for preparing the bio-carrier are:

[0066] S1. Mix 5 g of polyvinyl alcohol and 100 mL of water in a constant temperature water bath at 120° C. and stir (100 rpm) for 2 h until the polyvinyl alcohol is completely dissolved to obtain a polyvinyl alcohol aqueous solution;

[0067] S2, lowering the temperature of the polyvinyl alcohol aqueous solution to 25°C, continuing to stir, and when stirring until bubbles are at least a little, adding 5g of rare earth lanthanum oxide to the polyvinyl alcohol aqueous solution and dispersing it evenly to obtain a filler solution;

[0068] S3, the volume is 405cm 3 The polyurethane sponge was mixed with the filler solution, magnetically stirred for 30 minutes, and then dried (100°C, 12 hours). After drying, the incompletely fixed lanthanum oxide on its surface was repeatedly washed off in ultrapure water, and dried again (100°C, 12 hours). After cooling to room temperature, an enhanced MBBR denitrification rare earth modified bio-carrier was obtained.

[0069] Test example

[0070] The bio-carriers prepared in Example 1 (rare earth group) and Comparative Example 1 (blank group) were cut into samples with a size of 30 mm×30 mm×10 mm and used as fillers in the MBBR process for sewage treatment.

[0071] Source of sewage and main parameters: The test water uses artificially prepared simulated domestic sewage, and the chemical oxygen demand (COD Cr ) is 400~500mg / L, NH 4+- N is 40-50 mg / L, TP is 4.0-4.5 mg / L. NaHCO3 is added to provide sufficient alkalinity to ensure that the nitrification reaction in the reactor is not affected by pH inhibition. Trace element nutrient solution is added, and 1 mL of trace elements is added to 1L of water. The inoculated sludge is the activated sludge in the aeration tank of a sewage plant in Baotou City, and its mixed liquor suspended solid concentration (MLSS) is about 6800 mg / L.

[0072] The solution is as follows:

[0073] In this experiment, two identical MBBR reactors were set up for parallel operation. The reactor is made of plexiglass. The main body of the reactor is a cuboid with a diameter of 30 cm and a height of 70 cm, and the effective volume is 52 L. The R1 reactor is added with a rare earth lanthanum modified carrier (rare earth group), and the R2 reactor is added with a common carrier (blank group). The carrier filling rate is 30%. An aeration plate is installed at the bottom of the reactor, and an air compressor is used for aeration. The aeration volume is controlled by a valve to adjust the dissolved oxygen (DO) in the reactor. The water inlet flow is controlled by a peristaltic pump. MBBR device such as Fig. 9 shown.

[0074] Figure 3 The SEM images of the rare earth modified bio-carrier for enhanced MBBR denitrification prepared in Example 1, wherein (a) is a SEM image of the rare earth modified carrier magnified 30 times, and (b) is a SEM image of the rare earth modified carrier magnified 2000 times; Figure 4 The following are SEM images of common biological carriers, where (a) is a SEM image of a common carrier magnified 30 times, and (b) is a SEM image of a common carrier magnified 2000 times. Figure 3-4 It can be seen that the enhanced MBBR denitrification rare earth modified bio-carrier prepared in Example 1 has a significantly increased roughness compared with the bio-carrier prepared in Comparative Example 1, which can accelerate the biofilm formation process and greatly improve the effectiveness and efficiency of the biological treatment system. The new rare earth lanthanum modified bio-carrier has lower operating costs and higher treatment efficiency, achieving economic and social benefits.

[0075] Determination of microbial biomass per unit mass of carrier

[0076] After the biofilm carrier is taken out, it is rinsed with deionized water several times to remove loose impurities on the carrier surface; the sample is then placed in a 1mol / L NaOH solution and heated in a water bath at 60°C for 30 minutes; after heating in the above solution, it is ultrasonicated at a power of 100W for 30 minutes to make the biofilm adhering to the carrier fall off as much as possible; finally, the detached biofilm mixture is filtered through a 0.45μm filter membrane (the filter membrane has been numbered and weighed in advance), the filter paper and the treated carrier are placed in an oven, and baked at 80°C for 30 minutes before weighing. The biomass attached to the unit mass of the biological carrier can be obtained by calculating the ratio of the difference in mass before and after filtration of the filter paper to the mass of the blank carrier.

[0077] Figure 5 Comparative pictures of wastewater treated with the biological carriers prepared in Example 1 (left) and Comparative Example 1 (right) as fillers. Figure 6 The weight change of the bio-carriers prepared in Example 1 and Comparative Example 1 when used as fillers in the MBBR process is shown in FIG. Figure 5-6 It can be seen that compared with the biomass of the blank group in Comparative Example 1, it can be clearly seen that the addition of the rare earth-modified biological carrier of the rare earth group in Example 1 is conducive to the accumulation of free microorganisms on the surface of the biological carrier.

[0078] Figure 7 The ammonia nitrogen concentration and ammonia nitrogen removal rate when the bio-carriers prepared in Example 1 and Comparative Example 1 are used as fillers in the MBBR process, wherein (a) is the ammonia nitrogen concentration, (b) is the ammonia nitrogen removal rate, and Figure 7 As can be seen from (a) and (b), the average concentration of ammonia nitrogen in the inlet water is 40 mg / L, and the average concentration of ammonia nitrogen in the outlet water of the reactors of Example 1 and Comparative Example 1 is 6 mg / L and 1 mg / L, respectively, and the average removal rates are 96.1% and 86.2%, respectively. The removal effect of ammonia nitrogen by the rare earth group is always higher than that of Comparative Example 1. The ammonia nitrogen removal rate of Example 1 is 10% higher than that of Comparative Example 1, and the effluent water quality can meet the standard.

[0079] Figure 8 COD when the bio-carriers prepared in Example 1 and Comparative Example 1 are used as fillers in MBBR process Cr Concentration and COD Cr Removal rate, where (a) is COD Cr concentration, (b) is COD Cr Removal rate, by Figure 8 As can be seen from (a) and (b), the influent COD Cr The average concentration is about 400 mg / L. When the reactor is running stably, the effluent COD of Example 1 and Comparative Example 1 Cr The average concentrations were 43 mg / L and 26 mg / L, and the average removal rates were 94.1% and 90.3%, respectively.Cr The removal effect of Example 1 is always higher than that of Comparative Example 1. Cr The removal rate is increased by 4% compared with the comparative example 1, and the effluent water quality can meet the standard.

[0080] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A rare earth modified bio-carrier for enhancing MBBR denitrification, characterized in that: The rare earth modified bio-carrier for strengthening MBBR denitrification has a polyurethane sponge as a skeleton and polyvinyl alcohol and lanthanum oxide as fillers.

2. The rare earth modified bio-carrier for enhanced MBBR denitrification according to claim 1, characterized in that: The usage ratio of the polyurethane sponge, polyvinyl alcohol and lanthanum oxide is 405cm 3 :5g:15g.

3. A method for preparing a rare earth modified bio-carrier for enhanced MBBR denitrification according to claim 1 or 2, characterized in that the steps include: Mixing polyvinyl alcohol and water, and stirring at a constant temperature until the polyvinyl alcohol is completely dissolved, to obtain a polyvinyl alcohol aqueous solution; Dispersing lanthanum oxide evenly in a polyvinyl alcohol solution to obtain a filler solution; The polyurethane sponge is immersed in the filler solution, stirred by magnetic force, and then dried to obtain the enhanced MBBR denitrification rare earth modified bio-carrier.

4. The preparation method according to claim 3, characterized in that: The mass ratio of the polyvinyl alcohol to water is 5:

100.

5. The preparation method according to claim 3, characterized in that: The temperature of the constant temperature stirring is 120° C. and the rotation speed is 100 rpm.

6. The preparation method according to claim 3, characterized in that: The magnetic stirring time is 30 min.

7. The preparation method according to claim 3, characterized in that: The drying temperature is 100°C.

8. Use of the rare earth modified bio-carrier for enhanced MBBR denitrification as claimed in claim 1 or 2 as a filler in MBBR process.

9. A method for improving the denitrification effect of MBBR process filler MBBR, characterized in that the steps include: Mixing polyvinyl alcohol and water, and stirring at a constant temperature until the polyvinyl alcohol is completely dissolved, to obtain a polyvinyl alcohol aqueous solution; Dispersing lanthanum oxide evenly in a polyvinyl alcohol solution to obtain a filler solution; The polyurethane sponge is immersed in the filler solution, stirred by magnetic force, and then dried to obtain a rare earth modified bio-carrier for enhanced MBBR denitrification; The rare earth modified bio-carrier for enhancing MBBR denitrification is used as a filler in the MBBR process.

10. A method for improving the biofilm formation speed and effect of MBBR process fillers, characterized in that the steps include: Mixing polyvinyl alcohol and water, and stirring at a constant temperature until the polyvinyl alcohol is completely dissolved, to obtain a polyvinyl alcohol aqueous solution; Dispersing lanthanum oxide evenly in a polyvinyl alcohol solution to obtain a filler solution; The polyurethane sponge is immersed in the filler solution, stirred by magnetic force, and then dried to obtain a rare earth modified bio-carrier for enhanced MBBR denitrification; The rare earth modified bio-carrier for enhancing MBBR denitrification is used as a filler in the MBBR process.

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