CN115974528B - An asymmetric solid waste-based ceramic catalytic membrane and its preparation method and application - Google Patents

Abstract

The invention discloses an asymmetric solid waste-based ceramic catalytic membrane and a preparation method and application thereof. The asymmetric solid waste-based ceramic catalytic membrane comprises a bottom support, a middle high-precision separation membrane layer and a top catalytic membrane layer; the support body is obtained by extrusion molding and sintering of raw materials including high-alumina fly ash and/or gasified slag and stone waste; the high-precision separation membrane layer is obtained by spray forming and sintering raw materials including high-alumina fly ash and stone waste; the catalytic membrane layer is prepared from raw materials including blast furnace slag, bayer process red mud, steel slag and manganese slag by spray forming and sintering, and the ceramic catalytic membrane has the advantages of low raw material cost, good physical properties and catalytic function, and can effectively remove COD in printing and dyeing wastewater.

Description

An asymmetric solid waste-based ceramic catalytic membrane and its preparation method and application

Technical field

The invention relates to a ceramic catalytic membrane, specifically an asymmetric solid waste-based ceramic catalytic membrane, a preparation method thereof and an application of the ceramic catalytic membrane in degrading organic wastewater, and belongs to the technical field of new materials.

Background technique

As one of the important ways to solve the "water problem", ceramic membranes have gradually become the focus of development in the membrane water treatment industry. At present, most raw materials for preparing ceramic flat membranes are alumina, but alumina itself is expensive, resulting in high raw material costs. On the other hand, the firing temperature required for firing ceramic flat membranes with alumina is high, resulting in high firing costs. It is precisely because of the shortcomings of existing ceramic flat membranes such as high raw material costs and high energy consumption for firing that the product prices are high and the market competitiveness is insufficient. Cost issues limit the further development of ceramic membranes.

At the same time, another major obstacle to the development of ceramic membrane application technology is membrane fouling. Research shows that soluble microbial products (SMPs), extracellular polymers (EPS) and some microorganisms are the main causes of membrane fouling. Microbial cells adhere to the membrane surface to form colonies and eventually form biofilms. The formed biofilms can even be used Fungicides are also difficult to remove. The adsorption, blocking or accumulation of these pollutants in the membrane pores and membrane surface will reduce the membrane filtration efficiency and increase operating costs. Physical methods mainly remove reversible dirt, while chemical cleaning is an effective method for removing irreversible dirt. By adding a variety of oxidants, active oxygen components such as hydroxyl radicals and sulfate radicals are generated, which can decompose EPS and bacterial cells, release/decompose intracellular substances, and alleviate membrane fouling.

Membrane catalysis technology applies membrane technology to the field of catalytic reactions. It combines the membrane separation of catalysts and the catalytic decomposition of organic pollutants by free radicals. It uses the high catalytic activity and high hydrophilicity of surface catalysts to remove pollutants and effectively avoid catalysts. Secondary pollution of water bodies caused by difficulty in recycling is a promising method for treating refractory organic matter in water bodies. At present, research on the construction of catalytic membranes for refractory organic matter in water mainly focuses on photocatalytic membrane technology. However, photocatalytic technology relies entirely on light sources and is difficult to apply in actual wastewater treatment. Compared with photocatalytic technology, advanced oxidation technology does not require the stimulation of a light source and can effectively remove organic pollutants in the presence of catalysts and oxidants.

However, most advanced oxidation-catalytic membranes are symmetrical membranes with often low compressive strength, poor flushing and backwashing capabilities, and unsatisfactory recycling effects. Compared with symmetrical ceramic membranes, asymmetrical ceramic membranes are stronger and less likely to break. Asymmetric carrier membranes usually consist of a three-layer membrane structure: the first layer is a porous carrier, that is, the support layer, which is mainly to ensure that the ceramic membrane has sufficient mechanical strength. At the same time, the support layer has relatively large pore sizes and relatively large diameter. High porosity reduces the resistance to fluid transportation and increases fluid permeability flux; the second layer is the transition layer, that is, the middle layer. The middle transition layer is a structure between the porous support layer and the separation layer to prevent catalytic activity. During the layer preparation process, the particles penetrate into the support layer. Due to the existence of the intermediate transition layer, the pore size of the support layer should be made larger to reduce the resistance to material transport; the third layer is the catalytic layer, which can be loaded by various methods. on a porous support or transition layer.

. Domestic and foreign countries have used the resource attributes of solid waste to prepare various building materials. However, solid waste raw materials contain rich transition metal elements or catalytic components, which cannot be used to the maximum value as raw materials for building materials.

Contents of the invention

In view of the shortcomings of the existing technology, the first object of the present invention is to provide an asymmetric solid waste-based ceramic catalytic membrane. The ceramic catalytic membrane not only has advanced oxidation catalytic function, but also has excellent physical properties and a bending strength of up to 32～35MPa, porosity 30～35%, average pore diameter of the support body is 1.5～2μm, and average pore diameter of the membrane plate is 80～100nm, which meets the requirements for the treatment and use of organic wastewater.

The second object of the present invention is to provide a method for preparing an asymmetric solid waste-based ceramic catalytic membrane. This method uses solid waste as the main raw material, has low cost, low sintering temperature, low energy consumption, and is beneficial to large-scale production. scale production.

The third object of the present invention is to provide an application of an asymmetric solid waste-based ceramic catalytic membrane in catalyzing the degradation of organic wastewater by hydrogen peroxide and citric acid. The ceramic catalytic membrane can catalyze the degradation of organic wastewater by hydrogen peroxide and citric acid. The wastewater undergoes advanced oxidation and has a good catalytic oxidative degradation effect on mineral processing wastewater, printing and dyeing wastewater, etc.

In order to achieve the above technical objectives, the present invention provides an asymmetric solid waste-based ceramic catalytic membrane, which includes a bottom support body, a middle high-precision separation membrane layer and a top catalytic membrane layer; the support body is composed of high-aluminum pulverized coal The raw material I including ash and/or gasified slag and stone waste is obtained by extrusion molding and sintering; the high-precision separation membrane layer is formed by spraying and sintering the raw material II including high-aluminum fly ash and stone waste. Obtained; the catalytic film layer is obtained by spray forming and sintering raw materials III including blast furnace slag, Bayer process red mud, steel slag and manganese slag.

In the asymmetric solid waste-based ceramic catalytic membrane of the present invention, the support body is mainly sintered from main raw materials such as high-aluminum fly ash (or gasification slag) and stone waste. The high-aluminum fly ash or gasification slag has relatively high The high aluminum-silicon content prevents the support from experiencing large sintering shrinkage during high-temperature sintering, thereby ensuring that the support has a certain sintering temperature range and is suitable for industrial kiln firing. Stone waste mainly contains some Alkaline oxides can reduce the sintering temperature of the support, and the use of high-aluminum fly ash or gasified slag and stone waste can be used to sinter the support with better mechanical properties and porosity.

In the asymmetric solid waste-based ceramic catalytic membrane of the present invention, the high-precision separation membrane layer is mainly sintered from main raw materials such as high-aluminum fly ash and stone waste. The high-precision separation membrane layer serves as an intermediate transition layer, and its main raw materials are The raw materials of the support body are consistent, which can improve the compatibility and bonding force between layers.

In the asymmetric solid waste-based ceramic catalytic membrane of the present invention, the catalyst in the catalytic membrane layer is sintered from main raw materials such as blast furnace slag, red mud, steel slag, manganese slag, etc., wherein the blast furnace slag contains titanium dioxide, which can impart photocatalytic effect to the membrane layer , when the water cleanliness is high, the catalytic function can be improved with the help of ultraviolet irradiation; red mud, steel slag, and manganese slag contain a large amount of transition metals and rare metal elements, which can add metal catalytic functions to the film layer. When the cleanliness is poor, In water bodies, metal catalytic function plays a major role. More specifically, blast furnace slag, red mud, steel slag and manganese slag are rich in catalytically active metals, such as iron, manganese, titanium, etc. The combination of these metals forms a synergistic catalytic system, which can improve the catalytic effect. Moreover, these waste residues also contain a lot of silicon-aluminum components, which are conducive to solid-phase sintering molding. At the same time, Bayer process red mud contains a lot of alkaline substances, which can play a fluxing role in the initial sintering stage of the catalytic film layer, giving the catalytic film layer better mechanical strength. Steel slag can provide calcium and magnesium elements for the catalytic film layer. Acid and alkali resistance brings beneficial effects. At the same time, the introduction of calcium and magnesium can produce a eutectic with the aluminum and silicon in blast furnace slag and manganese slag, which can further reduce the sintering temperature of the film layer.

As a preferred solution, the raw material I includes 50-70 parts of high-aluminum fly ash and/or gasification slag, 15-30 parts of stone waste, 2-4 parts of barium slag, 5-9 parts of pore-forming agent, 4 to 8 parts of binding agent, 3 to 6 parts of lubricant, 0.5 to 1 part of release agent, 2 to 4 parts of water retaining agent, and 15 to 25 parts of water. High-aluminum fly ash or gasified slag mainly provides aluminum-siliceous components. If its proportion is too low, it will affect the mechanical strength of the molding and support body. Stone waste has a lower melting temperature and contains certain alkaline substances and glue. The condensation active material can improve the performance of the clay material and facilitate molding during the green body clay material stage, and can be used as a flux in the subsequent sintering process. However, its addition amount should not be too high, which may easily lead to partial glass formation on the support body. , which affects the appearance quality and performance. When the content is too high, the strength of the support body is low during sintering and is easy to burst. When the proportion is too low, it not only affects the molding of the support body, but also increases the sintering temperature. Barium slag is mainly based on the fact that solid waste contains radioactive elements or polluting heavy metal elements. The introduction of an appropriate amount of barium slag mainly plays a role in shielding radioactivity. However, when its content is too high, the shielding effect on radioactivity is not good. will continue to increase, on the contrary, the shielding effect will be reduced, and too high a content will affect the strength of the support. When its content is too low, it will cause the dissolution content of heavy metals in the support to exceed the standard, and will cause the product to be highly radioactive, affecting production and sales. limit. Therefore, when the proportion of stone waste is too high, it is necessary to introduce a small amount of barium slag to shield and absorb the trace amounts of radionuclides in the stone waste to further ensure the safety of the product.

As a preferred solution, the pore-forming agent includes at least one of starch, magnesium carbonate, calcium carbonate, and dolomite.

As a preferred solution, the binder includes at least one of cellulose, polyvinyl alcohol, and polyacrylate.

As a preferred solution, the lubricant includes long-chain fatty acid methyl ester.

As a preferred solution, the release agent includes sodium stearate.

As a preferred solution, the water retaining agent includes glycerin.

As a preferred solution, the stone waste material is stone cutting waste material, such as granite stone powder.

As a preferred solution, the aluminum content of the high-aluminum fly ash is >37wt%, the total silicon and aluminum content is >80wt%, and the calcium content needs to be <3wt%.

As a preferred solution, the aluminum content of the gasified slag is >40wt%, and the total silicon and aluminum content is >85wt%.

The gasified slag, high-aluminum fly ash and stone waste in the support raw materials of the present invention are wet-milled using a ball mill to a particle size of 8-12 μm (rotation speed 250-300 r/min, time varies according to the original particle size). After ball milling After drying, use an air classifier to screen and remove oversized and undersized particles to ensure that the mass proportion of particles in the particle size range of 8 to 12 μm is >90%.

As a preferred solution, the particle size of the barium slag is 0.3-0.4 μm.

As a preferred solution, the raw material II includes the following components by mass: 50 to 75 parts of high-aluminum fly ash, 10 to 15 parts of stone waste, 2 to 4 parts of binder, 0.1 to 0.5 parts of dispersant, and ammonia water 1 to 2 servings. Under the preferred ratio, the pore size distribution of the high-precision separation membrane layer can be effectively adjusted to be optimal, and the average pore size can be controlled between 120 and 150 nm.

As a preferred solution, the particle size of high-aluminum fly ash and stone waste in the raw material II is 0.7-1.7 μm.

The thickness of the high-precision separation membrane layer of the present invention is 15 to 20 μm.

As a preferred option, the raw material II also contains water, and the ratio of the amount of water added to the solid mass is about 2 to 2.5:1.

As a preferred solution, the adhesive includes at least one of PVA and PVB;

As a preferred embodiment, the dispersant includes at least one of sodium metasilicate and ammonium polyacrylate.

As a preferred solution, the raw material III includes the following components by mass: 50 to 75 parts of catalytic material, 4 to 6 parts of binder, 0.5 to 1 part of dispersant, and 1 to 2 parts of ammonia; the catalytic material is composed of Blast furnace slag, Bayer process red mud, steel slag and manganese slag are composed according to the mass ratio of 15~25:7~13:10~15:20~25. The composition of catalytic materials has a relatively large impact on their catalytic performance. Blast furnace slag mainly provides titanium sources, while Bayer process red mud, steel slag and manganese slag mainly provide iron, manganese and other transition metal sources. There is a gap between these catalytically active metals. The proportion needs to be coordinated to give it excellent catalytic activity. In addition, the melting temperature of Bayer process red mud is relatively low. When the amount of red mud added is too high, it will cause other particles to be wrapped in the liquid phase, thus affecting the catalytic effect, while steel slag It is used to adjust the material composition and increase a small amount of metal elements at the same time. The addition ratio of blast furnace slag and manganese slag is determined according to their titanium content and manganese content to achieve the best catalytic effect.

As a more preferred solution, the binder includes polyvinyl alcohol.

As a more preferred solution, the dispersant includes polyacrylic acid.

The four raw materials of blast furnace slag, Bayer process red mud, steel slag and manganese slag in the catalytic film layer of the present invention are first crushed and screened to remove larger particles and impurity particles, and then placed in a ball mill for wet ball milling to a particle size of 10 μm, and then dried After drying, use a jet mill to further grind to a particle size of 0.7-0.9 μm and dry.

The thickness of the catalytic film layer of the present invention is 25-35 μm.

The invention also discloses a method for preparing an asymmetric solid waste-based ceramic catalytic membrane, which method includes the following steps:

1) After mixing the raw materials I, perform aging, extrusion molding, drying and sintering I in sequence to obtain a support body;

2) After wet grinding the raw material II, spray I onto the surface of the support, and then sinter II to obtain a high-precision separation membrane layer;

3) After wet grinding raw material III, spray II onto the surface of the high-precision separation membrane layer, and then sinter III to obtain a catalytic membrane layer;

As a preferred solution, the aging conditions are: temperature is 20-25°C, humidity is 50±10rh%, and time is 24-36 hours.

As a preferred solution, the drying conditions are: drying in a microwave drying manner at 160-180°C for 1-3 hours. Microwave drying makes the inside and outside of the support dry evenly to prevent cracking.

As a preferred solution, the conditions for sintering I are: the temperature is 1300-1350°C and the time is 1.5-2.5 hours.

As a preferred solution, the conditions for sintering II are: the temperature is 1100-1200°C and the time is 1.5-2.5 hours. The aggregate particle size in raw material II is smaller, and the energy required for sintering is lower, so a lower sintering temperature can give it sintering strength.

As a preferred solution, the sintering III conditions are as follows: the temperature is 600-850°C and the time is 0.5-1.5 hours.

As a preferred solution, the conditions for spraying I are: the spraying pressure is 0.35-0.45MPa, the number of spraying layers is 2-4, and the total thickness of spraying is 15-20 μm. The thickness of the high-precision separation membrane layer will affect the porosity and pore size of the entire ceramic catalytic membrane, so its spraying thickness needs to be controlled within an appropriate range.

As a preferred solution, the conditions for spraying II are: the spraying pressure is 0.35-0.6MPa, the number of spraying layers is 3-4, and the total spraying thickness is 25-35 μm. The thickness of the catalytic film layer will affect the catalytic activity of the entire ceramic catalytic film. The higher the thickness of the catalytic film layer, the stronger the catalytic activity it shows. However, if the thickness of the catalytic film layer is too thick, it will affect its water permeability, so the spraying thickness needs to be Control within an appropriate range.

The ammonia water used in the present invention is industrial ammonia water.

The invention also provides the application of an asymmetric solid waste-based ceramic catalytic membrane, which is used to catalyze the degradation of organic wastewater by hydrogen peroxide and citric acid.

As a preferred solution, the organic wastewater includes mineral processing wastewater and/or printing and dyeing wastewater.

As a preferred solution, the ambient temperature of the degradation is 20 to 30°C, the time is 30 to 50 minutes depending on the concentration of pollutants, the amount of citric acid added is 0.5 to 1.5g/L, and the hydrogen peroxide is added in the form of hydrogen peroxide. Taking industrial hydrogen peroxide (30%) as an example, the addition amount is 1 to 7.5g/L, and the removal rate of COD organic pollutants within the reaction time reaches more than 95%.

Compared with the existing technology, the beneficial effects brought by the technical solution of the present invention are:

The support body, high-precision separation membrane layer and catalytic membrane layer of the asymmetric solid waste-based ceramic catalytic membrane of the present invention all use industrial solid waste as the main raw material, avoiding the use of traditional alumina raw materials, greatly reducing costs, and having absolute market competitiveness.

The main raw materials of the support body and the high-precision separation membrane layer in the asymmetric solid waste-based ceramic catalytic membrane of the present invention are high-aluminum fly ash and stone waste. The high-aluminum fly ash mainly provides aluminum silicon, which can make the support body It will produce a large sintering shrinkage, ensuring that the support body has a certain sintering temperature range, which can be suitable for industrial kiln firing. The stone waste contains some alkaline oxides, which can reduce the firing temperature, and the catalytic film layer contains catalytic The material is composed of blast furnace slag, red mud, steel slag and manganese slag. Titanium dioxide can be introduced into the blast furnace slag to make the film layer photocatalytic. When the water purity is high, ultraviolet light irradiation can be used to improve the catalytic function; red mud, steel slag , Manganese slag contains a large amount of transition metals and rare metal elements, which can add metal catalytic function to the film layer. In water with poor cleanliness, the metal catalytic function plays a major role. To sum up, the present invention completely utilizes industrial solid waste to construct a ceramic catalytic membrane with good mechanical strength, appropriate porosity and dual catalytic effect.

The asymmetric solid waste-based ceramic catalytic membrane of the present invention is used for the treatment of printing and dyeing organic wastewater, and the removal rate of COD organic pollutants reaches more than 95% in a short period of time.

Description of the drawings

Figure 1 shows photos of samples at different stages of ceramic catalytic membrane preparation. Both the separation membrane layer and the catalytic membrane layer have good adhesion and high bonding strength.

Figure 2 is a schematic structural diagram of a ceramic catalytic membrane. The asymmetric catalytic membrane is mainly composed of a support body + a high-precision separation membrane layer + a catalytic membrane layer.

Figure 3 shows the treatment effect of ceramic catalytic membrane on printing and dyeing wastewater. It can be seen that the reaction time of different thicknesses of catalytic layers to treat organic pollutants is slightly different, but the degradation of pollutants can basically be achieved.

Detailed ways

The following specific examples are intended to further illustrate the present invention in detail, but are not intended to limit the scope of the claims.

The chemical reagents involved in the following examples are all conventional commercially available raw materials unless otherwise specified.

The aluminum content of high-aluminum fly ash involved in the following examples is 39wt%, the total silicon and aluminum content is 85wt%, and the calcium content is 2.5wt%.

The aluminum content of the gasified slag involved in the following examples is 44wt%, and the total silicon and aluminum content is 87wt%.

Example 1

Step 1: Based on 10g each, weigh 50 parts of 9μm high-aluminum fly ash, 20 parts of 9μm granite stone powder, 3 parts of 2μm barium slag, 8 parts of dolomite and 5 parts of cellulose, and mix them in a mixer for 25 minutes ; Then weigh 3 parts of FAME fatty acid methyl ester with 99.9% purity, 0.5 parts of sodium stearate, 2 parts of glycerin, and 20 parts of water, stir for 30 minutes with a stirrer, add to the mixer, and mix for 7 minutes; the mud material is at 25°C. After aging for 24 hours at 50 rh%, the support body was prepared by extrusion molding using an extruder. After molding, it was microwave heated to 165°C and dried for 2 hours, and then fired in a muffle furnace at 1300°C for 2 hours to obtain the support body.

Step 2: Based on 10g per portion, weigh 75 parts of 1.5 μm high alumina fly ash, 15 parts of 1.3 μm granite stone powder, 3 parts of PVA, 0.5 parts of ammonium polyacrylate, 1.3 parts of industrial ammonia, and 220 parts of water. Weigh well. Then use a ball mill to grind and mix for 1.5 hours. The slurry is prepared and sprayed with 2 layers of film at a pressure of 0.4 MPa. After the film layer is naturally air-dried, it is fired at 1150°C for 1.5 hours before use.

Step 3: In parts by weight, weigh 17 parts of blast furnace slag with 20% titanium content, 13 parts of Bayer process red mud, 14 parts of steel slag, and 22 parts of manganese slag. Use a rapid mill to pre-grind it to less than 10 μm, and then use a jet pulverizer. Further grind to a particle size of 0.75 μm to prepare the catalyst; then weigh 65 parts of the catalyst, 5 parts of polyvinyl alcohol, 0.5 parts of ammonium polyacrylate, 1.5 parts of industrial ammonia, and 160 parts of water. After weighing, use a ball mill to grind for 1.5 hours, and the slurry The material is prepared and sprayed with 3 layers of 0.4MPa coating. After infrared drying and firing at 800°C for 1 hour, a ceramic catalytic membrane is obtained.

Step 4: Select the printing and dyeing wastewater water body and treatment conditions. The wastewater (printing and dyeing wastewater mainly composed of aromatic hydrocarbons and heterocyclic compound dyes, COD concentration 800mg/L) has a water volume of 20L, add 60g of 30% industrial hydrogen peroxide, and 20g of citric acid. Put in the ceramic catalytic membrane module and react at 25°C for 50 minutes.

Control experimental group: Prepare ceramic catalytic membranes of different thicknesses according to the process in step 3. Specifically, the average thickness of the catalytic membrane layer is 25 μm, 30 μm and 35 μm respectively. The catalytic degradation performance of various thicknesses of ceramic catalytic membranes for wastewater is shown in Figure 3 shown.

Example 2

Step 1: Based on 10g each, weigh 50 parts of 12 μm gasified slag, 30 parts of 12 μm granite powder, 4 parts of 2 μm barium slag, 7 parts of starch, and 7 parts of cellulose, and mix them in a mixer for 25 minutes; weigh later Take 3 parts of FAME fatty acid methyl ester with 99.9% purity, 0.6 parts of sodium stearate, 2 parts of glycerin, and 20 parts of water, stir for 30 minutes with a stirrer, add to the mixer, and mix for 7 minutes; the mud is at 25°C, 50rh% After aging for 24 hours, use an extruder to prepare a support body by extrusion molding. After molding, microwave heating is performed at 165°C for drying for 2 hours, and a muffle furnace is used to bake at 1300°C for 2 hours to obtain the support body.

Step 2: Based on 10g per portion, weigh 50 parts of 1.5 μm high alumina fly ash, 10 parts of 1.3 μm granite powder, 3.5 parts of PVA, 0.5 parts of ammonium polyacrylate, 1.3 parts of industrial ammonia, and 150 parts of water, and weigh After grinding and mixing for 1.5 hours, use a ball mill to complete the slurry preparation. Spray 3 layers of coating at a pressure of 0.45MPa. After the film layer is naturally air-dried, it is fired at 1200°C for 1.5 hours before use.

Step 3: In parts by weight, weigh 50 parts of blast furnace slag with 20% titanium content, 15 parts of Bayer process red mud, 30 parts of steel slag, and 40 parts of manganese slag. Use a rapid mill to pre-grind it to less than 10 μm, and then use a jet pulverizer. Further grind to a particle size of 0.6 μm to prepare the catalyst; then weigh 75 parts of the catalyst, 5 parts of polyvinyl alcohol, 0.3 parts of sodium metasilicate, 1.5 parts of industrial ammonia, and 190 parts of water. After weighing, use a ball mill to grind for 1.5 hours. The slurry was prepared and sprayed with 4 layers of 0.6MPa coating. After infrared drying and firing at 800°C for 1 hour, a ceramic catalytic membrane was obtained.

Step 4: Select the printing and dyeing wastewater water body and treatment conditions. The amount of wastewater (printing and dyeing wastewater mainly composed of aromatic hydrocarbons and heterocyclic compound dyes, COD concentration 800mg/L) is 20L, and 100g of 30% industrial hydrogen peroxide and 30g of citric acid are added. Put in the ceramic catalytic membrane module and react at 25°C for 50 minutes.

Example 3

Step 1: Based on 10g each, weigh 70 parts of 9 μm gasified slag, 20 parts of 12 μm granite powder, 3 parts of 2 μm barium slag, 8 parts of magnesium carbonate, and 5 parts of cellulose, and mix them in a mixer for 25 minutes; Weigh 5 parts of FAME fatty acid methyl ester with 99.9% purity, 0.5 parts of sodium stearate, 3 parts of glycerin, and 20 parts of water, stir for 30 minutes with a stirrer, add to the mixer, and mix for 7 minutes; the mud is at 25°C, 50rh% After aging for 24 hours, use an extruder to extrusion mold to prepare a support body. After molding, microwave heating to 170°C dried for 2 hours, and a muffle furnace was used to bake at 1350°C for 1.5 hours to obtain the support body.

Step 2: Based on 10g per portion, weigh 50 parts of 2μm high alumina fly ash, 15 parts of 1.6μm granite powder, 3.5 parts of PVA, 0.5 parts of ammonium polyacrylate, 1.3 parts of industrial ammonia, and 140 parts of water. After weighing Use a ball mill to grind and mix for 1.5 hours. The slurry is prepared and sprayed with 4 layers of coating at a pressure of 0.35 MPa. After the film layer is naturally air-dried, it is fired at 1100°C for 1.5 hours before use.

Step 3: Weigh 15 parts of blast furnace slag, 13 parts of Bayer process red mud, 10 parts of steel slag, and 25 parts of manganese slag in parts by weight. After pre-grinding to less than 10 μm using a rapid mill, use a jet mill to further grind to particles. The catalyst is prepared with a diameter of 0.7 μm; then weigh 50 parts of the catalyst, 5 parts of polyvinyl alcohol, 0.5 parts of ammonium polyacrylate, 1.5 parts of industrial ammonia, and 130 parts of water. After weighing, use a ball mill to grind for 1.5h, and the slurry preparation is completed 0.5 Three layers of MPa spray coating were applied, and after infrared drying and firing at 750°C for 1.5 hours, a ceramic catalytic membrane was obtained.

Step 4: Select the printing and dyeing wastewater water body and treatment conditions. The wastewater (printing and dyeing wastewater mainly composed of aromatic hydrocarbons and heterocyclic compound dyes, COD concentration 800mg/L) has a water volume of 20L, add 30g of 30% industrial hydrogen peroxide, and 10g of citric acid. Put in the ceramic catalytic membrane module and react at 25°C for 50 minutes.

Example 4

Step 1: Based on 10g each, weigh 50 parts of 10 μm high-aluminum fly ash, 15 parts of 9 μm granite stone powder, 3 parts of 2 μm barium slag, 8 parts of calcium carbonate, and 5 parts of cellulose, and mix them in a mixer for 25 minutes. ; Then weigh 6 parts of FAME fatty acid methyl ester with 99.9% purity, 0.5 parts of sodium stearate, 2.5 parts of glycerin, and 20 parts of water, stir for 30 minutes with a stirrer, add to the mixer, and mix for 7 minutes; the mud material is at 25°C. After aging for 24 hours at 50 rh%, the support body was prepared by extrusion molding using an extruder. After molding, it was dried at 165°C for 2 hours, and fired in a muffle furnace at 1300°C for 2 hours to obtain the support body.

Step 2: Based on 10g per portion, weigh 75 parts of 1.5 μm high alumina fly ash, 10 parts of 1.3 μm granite powder, 3 parts of PVA, 0.5 parts of ammonium polyacrylate, 1.3 parts of industrial ammonia, and 200 parts of water. Weigh well. Then use a ball mill to grind and mix for 1.5 hours. The slurry is prepared and sprayed with 2 layers of coating at a pressure of 0.45 MPa. After the film layer is naturally air-dried, it is fired at 1150°C for 1.5 hours before use.

Step 3: Weigh 34 parts of blast furnace slag with 17% titanium content, 28 parts of Bayer process red mud, 28 parts of steel slag, and 44 parts of manganese slag in parts by weight. Use a rapid mill to pre-grind it to less than 10 μm, and then use a jet pulverizer. Further grind to a particle size of 0.75 μm to prepare the catalyst; then weigh 70 parts of the catalyst, 5 parts of polyvinyl alcohol, 0.5 parts of ammonium polyacrylate, 1.5 parts of industrial ammonia, and 160 parts of water. After weighing, use a ball mill to grind for 1.5 hours, and the slurry After the material preparation is completed, 4 layers of coating are sprayed with 0.4MPa. After infrared drying and firing at 650°C for 0.5h, a ceramic catalytic membrane is obtained.

Step 4: Select the printing and dyeing wastewater water body and treatment conditions. The wastewater (printing and dyeing wastewater mainly composed of aromatic hydrocarbons and heterocyclic compound dyes, COD concentration 800mg/L) has a water volume of 20L, add 150g of 30% industrial hydrogen peroxide, 30g of citric acid, and then release Insert the ceramic catalytic membrane module and react at 25°C for 50 minutes.

Comparative example 1

Step 1: Based on 10g per portion, weigh 50 parts of 9 μm high-aluminum fly ash, 3 parts of 2 μm barium slag, 8 parts of dolomite, and 5 parts of cellulose, and mix them in a mixer for 25 minutes; then weigh 99.9% 3 parts of pure FAME fatty acid methyl ester, 0.5 parts of sodium stearate, 2 parts of glycerin, 20 parts of water, use a stirrer to stir for 30 minutes, add to the mixer, mix for 7 minutes; the mud is aged for 24 hours at 25°C and 50rh% , use an extruder to prepare the support body by extrusion molding. After molding, microwave heating is performed at 165°C to dry for 2 hours, and a muffle furnace is used to bake at 1300°C for 2 hours to obtain the support body.

Step 2: Based on 10g per portion, weigh 75 parts of 1.5 μm high alumina fly ash, 15 parts of 1.3 μm granite stone powder, 3 parts of PVA, 0.5 parts of ammonium polyacrylate, 1.3 parts of industrial ammonia, and 220 parts of water. Weigh well. Then use a ball mill to grind and mix for 1.5 hours. The slurry is prepared and sprayed with 2 layers of film at a pressure of 0.4 MPa. After the film layer is naturally air-dried, it is fired at 1150°C for 1.5 hours before use.

Step 3: In parts by weight, weigh 17 parts of blast furnace slag with 20% titanium content, 13 parts of Bayer process red mud, 14 parts of steel slag, and 22 parts of manganese slag. Use a rapid mill to pre-grind it to less than 10 μm, and then use a jet pulverizer. Further grind to a particle size of 0.75 μm to prepare the catalyst; then weigh 65 parts of the catalyst, 5 parts of polyvinyl alcohol, 0.5 parts of ammonium polyacrylate, 1.5 parts of industrial ammonia, and 160 parts of water. After weighing, use a ball mill to grind for 1.5 hours, and the slurry The material is prepared and sprayed with 3 layers of 0.4MPa coating. After infrared drying and firing at 800°C for 1 hour, a ceramic catalytic membrane is obtained.

Step 4: Select the printing and dyeing wastewater water body and treatment conditions. The wastewater (printing and dyeing wastewater mainly composed of aromatic hydrocarbons and heterocyclic compound dyes, COD concentration 800mg/L) has a water volume of 20L, add 60g of 30% industrial hydrogen peroxide, and 20g of citric acid. Put in the ceramic catalytic membrane module and react at 25°C for 50 minutes.

Comparative example 2

Step 1: Based on 10g each, weigh 50 parts of 12 μm gasified slag, 30 parts of 12 μm granite powder, 4 parts of 2 μm barium slag, 7 parts of starch, and 7 parts of cellulose, and mix them in a mixer for 25 minutes; weigh later Take 3 parts of FAME fatty acid methyl ester with 99.9% purity, 0.6 parts of sodium stearate, 2 parts of glycerin, and 20 parts of water, stir for 30 minutes with a stirrer, add to the mixer, and mix for 7 minutes; the mud is at 25°C, 50rh% After aging for 24 hours, use an extruder to prepare the support body by extrusion molding. After molding, it is dried at 165°C for 2 hours, and fired in a muffle furnace at 1300°C for 2 hours to obtain the support body.

Step 2: Based on 10g per portion, weigh 50 parts of 1.5 μm high alumina fly ash, 10 parts of 1.3 μm granite stone powder, 3.5 parts of PVA, 0.5 parts of ammonium polyacrylate, 1.3 parts of ammonia, and 150 parts of water. Weigh well. Then use a ball mill to grind and mix for 1.5 hours. The slurry is prepared and sprayed with 3 layers of coating at a pressure of 0.45 MPa. After the film layer is naturally air-dried, it is fired at 1200°C for 1.5 hours before use.

Step 3: Weigh 50 parts of blast furnace slag, 30 parts of steel slag, and 40 parts of manganese slag in parts by weight, pre-grind them to less than 10 μm using a rapid mill, and then further grind them to a particle size of 0.6 μm using a jet mill to prepare a catalyst; Then weigh 75 parts of catalyst, 5 parts of polyvinyl alcohol, 0.3 parts of sodium metasilicate, 1.5 parts of ammonia, and 190 parts of water. After weighing, use a ball mill to grind for 1.5 hours. The slurry is prepared and sprayed with 4 layers of 0.6MPa coating. After infrared drying and firing at 800°C for 1 hour, a ceramic catalytic membrane was obtained.

Step 4: Select the printing and dyeing wastewater water body and treatment conditions. The amount of wastewater (printing and dyeing wastewater mainly composed of aromatic hydrocarbons and heterocyclic compound dyes, COD concentration 800mg/L) is 20L, and 100g of 30% industrial hydrogen peroxide and 30g of citric acid are added. Put in the ceramic catalytic membrane module and react at 25°C for 50 minutes.

Comparative example 3

Step 1: Based on 10g each, weigh 70 parts of 9 μm gasified slag, 20 parts of 12 μm granite powder, 3 parts of 2 μm barium slag, 8 parts of magnesium carbonate, and 5 parts of cellulose, and mix them in a mixer for 25 minutes; Weigh 5 parts of FAME fatty acid methyl ester with 99.9% purity, 0.5 parts of sodium stearate, 3 parts of glycerin, and 20 parts of water, stir for 30 minutes with a stirrer, add to the mixer, and mix for 7 minutes; the mud is at 25°C, 50rh% After aging for 24 hours, use an extruder to extrusion mold to prepare a support body. After molding, microwave heating to 170°C dried for 2 hours, and a muffle furnace was used to bake at 1350°C for 1.5 hours to obtain the support body.

Step 2: Based on 10g per portion, weigh 50 parts of 2μm high alumina fly ash, 15 parts of 1.6μm granite stone powder, 3.5 parts of PVA, 0.5 parts of ammonium polyacrylate, 1.3 parts of industrial ammonia, and 140 parts of water. Weigh well. Then use a ball mill to grind and mix for 1.5 hours. The slurry is prepared and sprayed with 4 layers of coating at a pressure of 0.35MPa. After the film layer is naturally air-dried, it is fired at 1100°C for 1.5 hours before use.

Step 3: Weigh 26 parts of Bayer process red mud and 50 parts of manganese slag in parts by weight. Use a rapid mill to pre-grind it to less than 10 μm, and then use a jet mill to further grind it to a particle size of 0.7 μm to prepare the catalyst; then weigh Take 50 parts of catalyst, 5 parts of polyvinyl alcohol, 0.5 parts of ammonium polyacrylate, 1.5 parts of industrial ammonia, and 130 parts of water. After weighing, use a ball mill to grind for 1.5 hours. The slurry is prepared to complete 3 layers of 0.5MPa spray coating. After infrared After drying and calcining at 750°C for 1.5 hours, a ceramic catalytic membrane was obtained.

Step 4: Select the printing and dyeing wastewater water body and treatment conditions. The wastewater (printing and dyeing wastewater mainly composed of aromatic hydrocarbons and heterocyclic compound dyes, COD concentration 800mg/L) has a volume of 20L, add 30g of 30% industrial hydrogen peroxide, and 10g of citric acid. Put in the ceramic catalytic membrane module and react at 25°C for 50 minutes.

Table 1 Performance comparison of ceramic catalytic membranes prepared in Examples 1 to 4 and Comparative Examples 1 to 3

Claims (7)

1. An asymmetric solid waste-based ceramic catalytic membrane, which is characterized in that: comprises a bottom support body, a middle high-precision separation membrane layer and a top catalytic membrane layer; the support body is obtained by extrusion molding and sintering of a raw material I containing high-alumina fly ash and/or gasified slag and stone waste; the high-precision separation membrane layer is obtained by spray forming and sintering a raw material II containing high-alumina fly ash and stone waste; the catalytic film layer is obtained by spray forming and sintering a raw material III containing blast furnace slag, bayer process red mud, steel slag and manganese slag;

the raw material I comprises 50-70 parts of high-alumina fly ash and/or gasified slag, 15-30 parts of stone waste, 2-4 parts of barium slag, 5-9 parts of pore-forming agent, 4-8 parts of binder, 3-6 parts of lubricant, 0.5-1 part of release agent, 2-4 parts of water-retaining agent and 15-25 parts of water;

the raw material II comprises the following components in parts by mass: 50-75 parts of high-alumina fly ash, 10-15 parts of stone waste, 2-4 parts of binder, 0.1-0.5 part of dispersing agent and 1-2 parts of ammonia water;

the raw material III comprises the following components in parts by mass: 50-75 parts of catalytic material, 4-6 parts of binder, 0.5-1 part of dispersing agent and 1-2 parts of ammonia water; the catalytic material consists of blast furnace slag, bayer process red mud, steel slag and manganese slag according to the mass ratio of 15-25:10-15:10-15:20-25.

2. An asymmetric solid waste-based ceramic catalytic membrane according to claim 1, wherein:

the aluminum content of the Gao Lvfen coal ash is more than 37wt percent, the total silicon-aluminum content is more than 80wt percent, and the calcium content is less than 3wt percent;

the aluminum content of the gasified slag is more than 40wt percent, and the total silicon-aluminum content is more than 85wt percent;

the pore-forming agent comprises at least one of starch, magnesium carbonate, calcium carbonate and dolomite;

the binder comprises at least one of cellulose, polyvinyl alcohol and polyacrylate;

the lubricant comprises long chain fatty acid methyl esters;

the release agent comprises sodium stearate;

the water-retaining agent comprises glycerol.

3. An asymmetric solid waste-based ceramic catalytic membrane according to claim 2, wherein:

the binder comprises at least one of PVA and PVB;

the dispersing agent comprises at least one of sodium metasilicate and ammonium polyacrylate.

4. A method for preparing an asymmetric solid waste-based ceramic catalytic membrane according to any one of claims 1 to 3, which is characterized in that:

1) After uniformly mixing the raw material I, sequentially ageing, extrusion molding, drying and sintering the raw material I to obtain a support body;

2) After wet grinding, spraying the raw material II onto the surface of the support body, and then sintering the raw material II to obtain a high-precision separation membrane layer;

3) And (3) after wet grinding, spraying II on the surface of the high-precision separation membrane layer, and sintering III to obtain the catalytic membrane layer.

5. The method for preparing the asymmetric solid waste-based ceramic catalytic membrane according to claim 4, which is characterized in that:

the conditions of the aging are as follows: the temperature is 20-25 ℃, the humidity is 50+/-10 rh, and the time is 24-36 h;

the drying conditions are as follows: drying for 1-3 h at 160-180 ℃ in a microwave drying mode;

the conditions of the sintering I are as follows: the temperature is 1300-1350 ℃ and the time is 1.5-2.5 hours;

the conditions of the sintering II are as follows: the temperature is 1100-1200 ℃ and the time is 1.5-2.5 hours;

the conditions for sintering III are as follows: the temperature is 600-850 ℃ and the time is 0.5-1.5 hours.

6. The method for preparing the asymmetric solid waste-based ceramic catalytic membrane according to claim 5, which is characterized in that:

the conditions of the spraying I are as follows: the spraying pressure is 0.35-0.45 MPa, the number of spraying layers is 2-4, and the total spraying thickness is 15-20 mu m;

the conditions of the spraying II are as follows: the spraying pressure is 0.35-0.6 MPa, the number of spraying layers is 3-4, and the total spraying thickness is 25-35 mu m.

7. Use of an asymmetric solid waste-based ceramic catalytic membrane according to any one of claims 1 to 3, characterized in that: the catalyst is applied to catalyzing hydrogen peroxide and citric acid to degrade organic wastewater.