CN116874291B - Preparation method of polyethyleneimine modified MBBR denitrification ceramic filler - Google Patents

Abstract

The invention discloses a preparation method of a polyethyleneimine-modified MBBR denitrification ceramic filler. The method comprises the following steps: step 1, firstly manufacturing a ceramic plate support body which is processed into a rectangular porous shape; step 2, using a cutting machine to cut the ceramic plate support body into a plurality of rectangular hollow porous ceramic fillers; step 3, plugging part of the holes or all the holes on one side of each ceramic filler with ceramic slurry, and then sintering at high temperature to form a semi-lateral wall-flow ceramic filler; and step 4, coating the surface of the semi-lateral wall-flow ceramic filler with a nano-polyethyleneimine coating liquid to form a polyethyleneimine-modified MBBR denitrification ceramic filler. The MBBR denitrification ceramic filler has high hydrophilicity and strong adhesion to activated sludge, can efficiently attach cells, and forms a biofilm quickly and is not easy to fall off. The MBBR denitrification ceramic filler has not only strong decarbonation and ammonia nitrogen removal capabilities, but also strong denitrification capabilities, and truly has the capabilities of simultaneous nitrification and denitrification (SND).

Description

Preparation method of polyethyleneimine modified MBBR denitrification ceramic filler

Technical Field

The invention relates to the technical field of ceramic fillers, and in particular to a method for preparing a polyethyleneimine-modified MBBR denitrification ceramic filler.

Background Art

Moving bed biofilm reactor (MBBR), also called suspended filler biofilm reactor, is a wastewater treatment process that combines activated sludge method and biofilm treatment technology. It is also a fixed film method. By adding suspended fillers with a density close to that of water in the aerobic zone, the filler medium can effectively attach biomass and establish a variety of microbial populations. At the same time, MBBR fillers have a significant enrichment effect on microorganisms, such as nitrifying bacteria that grow slowly and have a long sludge age. Therefore, it can greatly enhance the removal of organic pollutants and nitrification capabilities of the activated sludge system.

At present, the material of most MBBR fillers is HDPE (high-density polyethylene). Although it has a high specific surface area and a certain degree of hydrophilicity, it can attach a large number of microorganisms in sewage, forming a 0.2-0.25 mm film layer on the surface, forming an outer film and an inner film, thereby diversifying the microbial population and forming an aerobic, anoxic and anaerobic environment on the filler. However, it still exposes many deficiencies in the long-term application of various actual sewage projects.

First, the enriched microorganisms can improve the ability to degrade organic matter (carbon removal) and oxidize ammonia nitrogen (nitrification), but to improve the denitrification ability, the denitrification ability of the traditional MBBR mainly depends on the inner film formed on the surface of the filler. Due to the problem of its own structure, the filler cannot retain sludge inside the filler. Therefore, to improve the denitrification ability, it is necessary to reduce the dissolved oxygen (DO) of the aerobic system. When the dissolved oxygen in the aerobic system is slightly higher, because the thickness of the biofilm layer is only 0.2-0.25 mm, the dissolved oxygen can penetrate the biofilm on the surface of the filler, making it difficult for the biofilm to generate anoxic zones. However, reducing the DO value of the system will affect the effect of carbon removal and nitrification, especially for wastewater with slightly higher chemical oxygen demand (COD) and ammonia nitrogen, which will result in substandard results. After searching, the invention patent CN111204864A, the invention name is: A MBBR filler and its preparation method discloses a new type of MBBR filler, the components of which include a hydrophilic substrate, a toughening agent, light calcium carbonate, a density regulator, biological nutrients, a bioactive agent and a biological enzyme activator. The COD removal rate is as high as 5%, and the ammonia nitrogen removal rate is as high as 95%, but no denitrification data is listed. After searching, the invention patent CN104961227A, the invention name is: a modified polyurethane suspended filler, preparation method and application thereof, although it also reports a high removal rate of nitrate nitrogen (denitrification) by the filler, but the data source is in a beaker or a small column reactor, basically using water distribution experiments, COD is very low and ammonia nitrogen and total nitrogen are not high water quality conditions, the operation cycle is very short, and some experimental data are directly added with microbial agents containing denitrifying bacteria, so it does not reflect the actual situation of the actual project as a whole, and therefore has no general reference value.

Second, the biofilm formation capacity needs to be further improved, and the ability to resist changes in sewage water quality load is weak. When the water quality deteriorates, the formed biofilm is prone to fall off.

Third, after long-term operation, there is a certain breakage rate, and it is difficult to clean after use, and the reusability is very poor.

Fourth, the high market price of traditional HDPE also restricts the large-scale application of MBBR filler in large sewage treatment plants, and its promotion and use are greatly limited.

Summary of the invention

The object of the present invention is to provide a method for preparing a polyethyleneimine-modified MBBR denitrification ceramic filler, which has high hydrophilicity and strong adhesion to activated sludge, can efficiently attach cells, form biofilm quickly and is not easy to fall off, and has not only strong decarbonation and ammonia nitrogen removal capabilities, but also strong denitrification capabilities, and truly has the ability of simultaneous nitrification and denitrification (SND). In addition, it also has the characteristics of simple and convenient cleaning, low cost, and high recyclability.

To achieve the above object, the present invention provides a technical solution: a method for preparing a polyethyleneimine-modified MBBR denitrification ceramic filler, comprising the following steps:

Step 1: First, a rectangular porous ceramic plate support is manufactured and processed.

The method for manufacturing the ceramic plate support body comprises the following steps:

1) Aluminum oxide, silicon carbide, zirconium oxide and cordierite with an average particle size of 0.2-50 μm and a mass percentage concentration of 92-96 wt% are used as raw materials for the support keel, 1-3 wt% of a high temperature binder, 1.5 wt% of a toughening agent and 1 wt% of a peptizer are added, and then 2 wt% of a pore former and 20 wt% of deionized water are added and mixed evenly;

2) After mixing, the mixture is put into a vacuum clay kneading machine for kneading, and then statically dried and put into a prefabricated mold in a molding machine to form a porous rectangular green body;

3) Place the prepared rectangular green body into a microwave dryer and dry for 1-2 hours at a drying temperature of 50-70°C;

4) After drying, the rectangular green body is fired at a temperature of 1300°C-1600°C to obtain a ceramic plate support with an average particle size of 10 μm;

Step 2: Use a cutting machine to cut the ceramic plate support into a plurality of rectangular hollow and porous ceramic fillers;

Step 3, plugging part or all of the holes on one side of each ceramic filler with ceramic slurry, and then sintering at high temperature to form a semi-lateral wall-flow ceramic filler;

Step 4, coating the surface of the semi-lateral wall-flow ceramic filler with a nano-polyethyleneimine coating liquid to prepare a polyethyleneimine-modified MBBR denitrification ceramic filler;

The specific steps are as follows:

(1) First, clean the surface of the semi-lateral wall-flow ceramic packing;

(2) preparing a coating liquid containing polyethyleneimine and an alkaline solution for modification;

(3) Then, the semi-lateral wall-flow ceramic filler is immersed in the polyethyleneimine coating liquid and the alkaline solution for modification by the infiltration method. With the help of capillary suction, the polyethyleneimine coating liquid and the modified alkaline solution are distributed to the membrane pores and surface of the semi-lateral wall-flow ceramic filler. Then, after infiltration, it is taken out and dried in a microwave heating device to obtain the polyethyleneimine-modified MBBR denitrification ceramic filler.

Further preferably, the high temperature binder is nano-calcium carbide.

Further preferably, the peptizing agent is sodium polyphosphate.

More preferably, the toughening agent is Si ₃ N _4.

Further preferably, the pore-forming agent is a mixture of fly ash and compost ash.

Further preferably, the alkaline substance added to the polyethyleneimine coating liquid and the alkaline solution for modification is sodium bicarbonate, and its mass percentage concentration is 0.5wt%.

Further preferably, the polyethyleneimide coating liquid is polyethyleneimide with a molecular weight of 1800.

Further preferably, a plurality of holes are provided on both sides of the ceramic plate support body, and a plurality of hollow slots opening downward are provided on the bottom of the ceramic plate support body.

A polyethyleneimine-modified MBBR denitrification ceramic filler prepared by the preparation method of the polyethyleneimine-modified MBBR denitrification ceramic filler comprises: a ceramic filler body, a nano-polyethyleneimine coating, pores, and a ceramic slurry plugging material; the ceramic filler body is hollow inside and open at the bottom, a plurality of holes are evenly arranged on both sides of the ceramic filler body, and part or all of the holes on one side of the ceramic filler body are blocked with the ceramic slurry plugging material.

Further preferably, the hole is a rectangular opening.

Further preferably, the surface of the ceramic filler body is coated with a polyethyleneimine coating.

Compared with the prior art, the present invention has the following beneficial effects:

1. The polyethyleneimine-modified MBBR denitrification ceramic filler of the present invention is hollow inside and open at the bottom. Rectangular openings are evenly arranged on both sides, wherein some or all of the holes on one side are blocked with ceramic slurry plugging materials, and the surface is coated with a polyethyleneimine coating. With such a structural design, since some or all of the holes cannot be passed through by wastewater and can only flow out through the other side wall, suspended sludge in the sewage accumulates in these holes, easily forming an anoxic environment, which is conducive to the denitrification. It not only has a strong decarbonization and ammonia nitrogen removal ability, but also has a strong denitrification ability, and truly has the ability of simultaneous nitrification and denitrification (SND).

2. The present invention is configured to contain polyethyleneimine and an alkaline solution for modification. Since polyethyleneimine contains a large number of alkaline amino functional groups and has a strong interaction with the ceramic surface, the semi-lateral wall flow ceramic filler is surface modified by capillary force using an infiltration method to obtain polyethyleneimine-modified MBBR denitrification ceramic filler. The average particle size of the finished product is 10 μm, the flexural strength is 30-70 MPa, the alkali resistance is ≥99.6%, and the acid resistance is ≥98.6%. After actual testing, the initial contact angle of the ceramic plate modified by polyethyleneimine is only 20°, and the water droplet contact angle is reduced to 0° within 2.2 s. The hydrophilicity of the unmodified ceramic plate depends on the large number of hydroxyl groups on the surface. The initial water droplet contact angle is about 35°, and the water droplet quickly penetrates into the material pores and decreases to 0 within 3.3 s. The data shows that the hydrophilicity of the ceramic plate modified by polyethyleneimine is stronger. This is because polyethyleneimine is a polycationic polymer, containing a large number of cationic primary amines, secondary amines and tertiary amines. It is positively charged in water and can adsorb anionic substances. It also has a strong affinity for protons. Because there are a large number of amino nitrogen atoms in its macromolecular chain that are easily protonated, the electrostatic interaction between it and the negatively charged particles is strong. Therefore, the polyethyleneimine-modified MBBR denitrification ceramic filler has high hydrophilicity. When the pH is between 6-8, polyethyleneimine has a strong positive charge. Under normal conditions, the cells in the activated sludge are negatively charged under neutral or alkaline conditions. Therefore, the high hydrophilicity and strong positive charge properties make the ceramic plates modified by polyethyleneimine have strong cell attachment ability.

3. The polyethyleneimine-modified MBBR denitrification ceramic filler of the present invention has high hydrophilicity and strong adhesion to activated sludge, can efficiently attach cells, form biofilm quickly and is not easy to fall off, and has not only strong decarbonation and ammonia nitrogen removal capabilities, but also strong denitrification capabilities, and truly has the ability of simultaneous nitrification and denitrification (SND).

4. The polyethyleneimine-modified MBBR denitrification ceramic filler of the present invention has a significantly improved treatment effect compared to the traditional MBBR filler added in the early stage. In the small-scale test conducted simultaneously, some fillers were taken out and soaked and cleaned with sodium hypochlorite. Further experiments found that the biofilm formation ability was still very strong, indicating that the polyethyleneimine-modified ceramic filler has a high reusability. The above facts show that the polyethyleneimine-modified denitrification ceramic filler of the present invention has obvious advantages, especially in the early projects of upgrading and transforming sewage treatment plants.

5. The polyethyleneimine-modified MBBR denitrification ceramic filler of the present invention is also characterized by simple and convenient cleaning, low cost and high recyclability.

Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a flow chart of the present invention;

FIG2 is a schematic structural diagram of a ceramic plate support body of the present invention;

FIG3 is a schematic diagram of the bottom structure of a ceramic plate support of the present invention;

FIG4 is another schematic diagram of the structure of the ceramic plate support of the present invention;

FIG5 is a schematic diagram of another bottom structure of a ceramic plate support of the present invention;

FIG6 is a schematic structural diagram of a polyethyleneimine-modified MBBR denitrification ceramic filler according to the present invention;

FIG7 is a schematic diagram of one side of FIG6 ;

FIG8 is a schematic diagram of the other side of FIG6 after ceramic slurry plugging is added;

FIG9 is a schematic diagram of the flow direction of sewage in the filler after the cross section of FIG8;

FIG10 is a bottom schematic diagram of FIG6 ;

FIG11 is a top schematic diagram of FIG6 ;

FIG12 is a scanning electron microscope photo of the polyethyleneimine-modified MBBR denitrification ceramic filler.

Among them, 1. Ceramic filler body; 2. Polyethyleneimine coating; 3. Holes; 4. Ceramic slurry plugging material.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Example 1

The present disclosure provides a method for preparing a polyethyleneimine-modified MBBR denitrification ceramic filler, as shown in FIG1 , comprising the following steps:

Step 1: First, a porous ceramic plate support body is manufactured and processed into a rectangular parallelepiped.

The method for manufacturing a ceramic plate support body comprises the following steps:

1) Aluminum oxide, silicon carbide, zirconium oxide and cordierite with an average particle size of 0.2-50 μm and a mass percentage concentration of 92-96 wt% are used as the raw materials of the support keel. Aluminum oxide has the characteristics of high mechanical strength, high hardness, high temperature resistance, chemical corrosion resistance and low price, so the content of aluminum oxide accounts for more than 88%. 1-3 wt% of high temperature binder is added in sequence, the high temperature binder is nano calcium carbide, 1.5 wt% toughening agent and 1 wt% peptizing agent are selected, the toughening agent is Si ₃ N ₄ , the peptizing agent is sodium polyphosphate (Na ₂ P ₃ O ₁₀ ), and then 2 wt% pore-forming agent and 20 wt% deionized water are added and mixed evenly, and the pore-forming agent is a mixture of solid waste (fly ash and compost ash).

2) After mixing, the mixture is put into a vacuum clay kneading machine for kneading, and then statically dried and put into a prefabricated mold in a molding machine to form a porous rectangular green body.

3) Place the prepared rectangular body into a microwave dryer and dry for 1-2 hours at a drying temperature of 50-70°C.

4) After drying, the rectangular green body is fired at a temperature of 1300℃-1600℃, and can be fired in a tunnel kiln to obtain a ceramic plate support with an average particle size of 10μm. After testing, the average particle size of the finished product is 10μm, the flexural strength is 30-70MPa, the alkali resistance is ≥99.6%, and the acid resistance is ≥98.6%.

Step 2: Use a cutting machine to cut the ceramic plate support into a plurality of rectangular hollow and porous ceramic fillers.

Step 3: Block some or all of the holes on one side of each ceramic filler with ceramic slurry, and then sinter at high temperature to form a semi-lateral wall-flow ceramic filler. The purpose of this structure is to enable the sewage to achieve semi-lateral wall-flow movement in the filler, and partially retain the suspended sludge in the sewage in the filler to form anoxic conditions, which is conducive to denitrification.

Step 4: coating the surface of the semi-lateral wall-flow ceramic filler with a nano-polyethyleneimine coating liquid, i.e., performing surface modification to prepare a polyethyleneimine-modified MBBR denitrification ceramic filler.

The specific steps are as follows:

(1) First, clean the surface of the semi-lateral wall-flow ceramic packing;

(2) A coating liquid containing polyethyleneimine and an alkaline solution for modification is prepared, wherein the alkaline substance added to the alkaline surface modifier is sodium bicarbonate, and its mass percentage concentration is approximately 0.5wt%; the thickness of the polyethyleneimine functional layer is 5-50 μm.

(3) Then, the semi-lateral wall-flow ceramic filler is immersed in the polyethyleneimine coating liquid and the alkaline solution for modification by the infiltration method. With the help of capillary suction, the polyethyleneimine coating liquid and the modified alkaline solution are distributed to the membrane pores and surface of the semi-lateral wall-flow ceramic filler. Then, after infiltration, it is taken out and dried in a microwave heating device to obtain the polyethyleneimine-modified MBBR denitrification ceramic filler, which has high hydrophilicity.

The pore size of the ceramic plate finally obtained is between 0.2-0.5μm. After actual testing, the initial contact angle of the semi-lateral wall-flow ceramic filler modified with polyethyleneimine (i.e., MBBR denitrification ceramic filler modified with polyethyleneimine) is only 20°, and the water drop contact angle is reduced to 0° within 2.2 s. The hydrophilicity of the unmodified ceramic filler depends on the large number of hydroxyl groups on the surface. The initial water drop contact angle is about 35°, and the water droplet quickly penetrates into the pores of the material and decreases to 0 within 3.3s. The data shows that the MBBR denitrification ceramic filler modified with polyethyleneimine is more hydrophilic. When the pH is between 6-8, polyethyleneimine has a strong positive charge. Under normal conditions, the cells in the activated sludge are negatively charged under neutral or alkaline conditions. Therefore, the high hydrophilicity and strong positive charge properties make the MBBR denitrification ceramic filler modified with polyethyleneimine have a strong cell attachment ability.

Example 2

The structure of the ceramic plate support is shown in Figure 2-3. There are multiple holes on both sides, and the bottom of the ceramic plate support is provided with multiple hollow slots that are open at the bottom. When cutting, the dotted lines are cut to obtain semi-lateral wall flow ceramic filler.

Example 3

The structure of the ceramic plate support body can also be shown in Figure 4-5. The bottom of the ceramic plate support body is provided with multiple hollow slots with openings at the bottom. Both side walls of the hollow slots are provided with multiple holes. When cutting, the dotted lines are cut to obtain semi-lateral wall flow ceramic filler.

Example 4

A polyethyleneimine-modified MBBR denitrification ceramic filler prepared by the preparation method of Example 1, as shown in Figures 6-11, includes: a ceramic filler body 1, holes 3, and ceramic mud plugging material 4; the ceramic filler body 1 is hollow inside and open at the bottom, and multiple holes 3 are evenly arranged on both sides of the ceramic filler body 1. Part or all of the holes on one side of the ceramic filler body 1 are blocked with ceramic mud plugging material 4, and the surface of the ceramic filler body is coated with a polyethyleneimine coating 2, wherein the holes are preferably rectangular openings.

As shown in Figure 9, the direction indicated by the arrow is the flow direction of sewage in the filler. Since some holes cannot be penetrated by wastewater and can only flow out through the other side wall, the suspended sludge in the sewage accumulates in these holes, easily forming an oxygen-deficient environment, which is conducive to denitrification.

Figure 12 is a scanning electron microscope photo of the MBBR denitrification ceramic filler modified with polyethyleneimine. It can be seen that a three-dimensional porous nano-coating structure is formed on the surface of the ceramic filler modified with polyethyleneimine. This structure can ensure the rapid passage of water molecules while intercepting suspended matter and biofilm in the sewage.

Example 5

In order to make the innovative features and high-efficiency and economic advantages achieved by the patent of this invention clearly understood, the following is a further detailed description combined with a specific implementation method of an actual sewage renovation project.

An early enterprise with an annual output of about 1,000 tons of ultrapure silica discharged about 60 cubic meters of various wastewater every day (a total of 3 streams of production wastewater, accounting for about 90% of the total water volume, and other wastewater accounting for about 10%), COD about 2447 mg/L, ammonia nitrogen about 165.3 mg/L, total nitrogen about 165.3 mg/L. Although the overall concentration of pollutants is not high, the biodegradability of the wastewater is poor, and the quality of production wastewater has changed to a certain extent. The effluent standard is ≤ sewage discharge into urban sewer water quality standard ≥ (GB/T 31962-2015) 1A grade standard, that is, COD ≤ 500 mg/L, BOD ₅ ≤ 300 mg/L, ammonia nitrogen ≤ 45 mg/L, total nitrogen ≤ 70 mg/L (total nitrogen was not required in the early stage), SS ≤ 400 mg/L. The process adopted by the sewage station is hydrolysis acidification + aerobic (O) process. After hydrolysis and acidification, the MBBR process is formed by adding traditional HDPE MBBR filler (Ø25*10 mm) into the aerobic tank. The size of the O tank is 180 m³.

An interception screen is provided between the connecting holes and the connecting holes between the O tank and the secondary sedimentation tank to prevent the MBBR filler from flowing with the water to the next tank body, and a backflush pipe is provided under the interception screen. After nearly one year of operation, the effluent COD and ammonia nitrogen are far lower than the effluent indicators, but the total nitrogen is seriously exceeded. However, since there was no requirement for total nitrogen in the early stage, the entire sewage station can meet environmental protection requirements. After 2020, the total nitrogen requirement will be met. Since there is no available area in the actual plant area, another anoxic tank cannot be built. The MBBR filler made of HDPE material used in the early stage had a total nitrogen removal rate of only 21.6%, resulting in the total nitrogen not meeting the standard. At the same time, a small amount of filler was severely damaged, and some fillers had membrane shedding, and the filler was difficult to clean and almost impossible to reuse. In the upgrading and transformation project, the polyethyleneimine-modified MBBR denitrification ceramic filler of the present invention was selected to form a new MBBR process. The stacking volume of the polyethyleneimine-modified MBBR denitrification ceramic filler in the biochemical pool is 38% of the effective volume of the reaction pool, which is basically the same as the dosage of the HDPE MBBR in the early stage, but the total investment of the filler is only two-thirds of the HDPE MBBR filler used in the early stage. After the tank was emptied, the inoculated sludge was the mud cake after the sludge plate and frame dewatering machine of the nearby urban sewage treatment plant (VSS24.5 mg/L, water content 80%). During the initial commissioning, domestic wastewater was simulated, and industrial glucose, urea and potassium dihydrogen phosphate were used as carbon sources, nitrogen sources and phosphorus sources. The ratio of COD:N:P = 200:5:1 was added, and trace element compounds (ferric chloride, copper sulfate pentahydrate, etc.) were added. After 5 days of ventilated cultivation, a thin layer of yellow-brown biofilm was found on the surface of the filler. Continuous water inflow was changed. After 16 days of operation, obvious biofilms were observed on the surface of the filler. Through microscopic examination, a large number of flagellates, fixed ciliates, bell worms, etc. and a small number of rotifers were observed in the biofilm. In addition, filamentous bacteria with long hyphae were found, which indicated that the biofilm was very successful. The successful biofilm period is about 4 days shorter than that of the previous traditional HDPE filler. After the biofilm is successfully formed, the raw water is added at an increase of 10% per day until it is operated with 100% raw water. After one year of operation, it was found that the breakage rate of the filler was very low, and there was almost no obvious film shedding phenomenon on the surface of the biofilm of the filler. The entire sewage treatment system operates stably. Not only can the COD removal rate be basically stabilized at about 94.3%, the ammonia nitrogen removal rate can reach about 94.8%, and the TN removal rate is basically stable at about 71.6%, which is significantly improved compared with the treatment effect of adding traditional MBBR fillers in the early stage. In the small-scale test conducted simultaneously, some fillers were taken out, soaked and cleaned with sodium hypochlorite, and further experiments found that the biofilm ability was still very strong, indicating that the polyethyleneimine-modified ceramic filler has a high reusability. The above facts show that the polyethyleneimine-modified MBBR denitrification ceramic filler of the present invention has obvious advantages, especially in the early projects of upgrading and transforming sewage treatment plants.

In the description of the present invention, it is necessary to understand that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims (9)

1. The preparation method of the polyethyleneimine modified MBBR denitrification ceramic filler is characterized by comprising the following steps of:

Step 1, firstly manufacturing and processing the ceramic plate support body into a cuboid porous ceramic plate support body,

The manufacturing method of the ceramic plate support comprises the following steps:

1) Taking aluminum oxide, silicon carbide, zirconia and cordierite with average grain diameter of 0.2-50 mu m as raw materials of the support keel, wherein the components of the aluminum oxide in the raw materials of the support keel account for more than 88%, adding a high-temperature binder, a toughening agent and a peptizing agent, and then adding a pore-forming agent and deionized water for uniform mixing;

2) Mixing, putting into a vacuum pugging machine for pugging, and then standing and drying, putting into a prefabricated mould in a forming machine for preparing a porous cuboid blank;

3) Placing the prepared cuboid blank into a microwave dryer, and drying for 1-2h at 50-70deg.C;

4) After drying, firing the cuboid blank at 1300-1600 ℃ to obtain a ceramic plate support with an average particle size of 10 mu m;

Step 2, cutting the ceramic plate support body into a plurality of cuboid hollow porous ceramic fillers by using a cutting machine;

A plurality of holes are formed in two sides of the ceramic plate support body, and a plurality of hollow slotted holes with openings at the lower parts are formed in the bottom of the ceramic plate support body;

Step3, plugging part or all of holes on one side of each ceramic filler with ceramic slurry, and then sintering and forming at high temperature to prepare half-lateral wall-flow ceramic filler;

Step 4, coating nano polyethyleneimine coating liquid on the surface of the semi-lateral wall-flow ceramic filler to prepare polyethyleneimine modified MBBR denitrification ceramic filler;

The method comprises the following specific steps:

(1) Firstly, cleaning the surface of the prepared half lateral wall-flow ceramic filler;

(2) A coating liquid containing polyethyleneimine and an alkaline solution for modification;

(3) And immersing the semi-lateral wall-flow ceramic filler into an alkaline solution containing the polyethyleneimine coating liquid and for modification by adopting an immersion method, distributing the alkaline solution containing the polyethyleneimine coating liquid and for modification to the holes and the surfaces of the semi-lateral wall-flow ceramic filler by virtue of capillary suction, immersing, then providing, and drying in microwave heating equipment to obtain the polyethyleneimine modified MBBR denitrification ceramic filler.

2. The method for preparing the polyethyleneimine modified MBBR denitrification ceramic filler according to claim 1, wherein the high-temperature binder is nano calcium carbide.

3. The method for preparing the polyethyleneimine modified MBBR denitrification ceramic filler according to claim 1, wherein the peptizing agent is sodium polyphosphate.

4. The method for preparing the polyethyleneimine modified MBBR denitrification ceramic filler according to claim 1, wherein the toughening agent is Si ₃N₄.

5. The method for preparing the polyethyleneimine modified MBBR denitrification ceramic filler according to claim 1, wherein the pore-forming agent is a mixture of fly ash and heap fat.

6. The method for preparing the polyethyleneimine modified MBBR denitrification ceramic filler according to claim 1, wherein the alkaline substance added to the polyethyleneimine coating solution and the alkaline solution for modification is sodium bicarbonate, and the mass percentage concentration of the alkaline substance is 0.5wt%.

7. The method for preparing a polyethyleneimine modified MBBR denitrification ceramic filler according to claim 1, wherein the polyethyleneimine has a molecular weight of one of 600, 1800, 10000.

8. A polyethyleneimine modified MBBR denitrified ceramic filler prepared by the method of preparing a polyethyleneimine modified MBBR denitrified ceramic filler according to any of claims 1-7, comprising: ceramic filler body, nano polyethylenimine coating, hole and ceramic slurry plugging material; the ceramic filler body is hollow and is opened at the lower part, a plurality of holes are uniformly formed in two sides of the ceramic filler body, and part or all of the holes on one side of the ceramic filler body are blocked by ceramic slurry.

9. The polyethyleneimine modified MBBR denitrification ceramic filler according to claim 8, wherein the ceramic filler body is coated with a polyethyleneimine coating.