High-strength porous water storage type waste gas treatment base material and preparation method thereof

Abstract

The invention relates to the technical field of waste gas treatment, in particular to a high-strength porous water storage type waste gas treatment base material and a preparation method thereof. The high-strength porous water storage type waste gas treatment base material comprises activated carbon subjected to activation treatment, zeolite subjected to modification treatment, silicon dioxide, calcium sulfate dihydrate, calcium oxide and aluminum powder. The material forms a hierarchical pore structure with three-dimensional communicated pore channels and high specific surface area, has better mechanical strength and lasting water storage and release functions, and can provide a stable adhesion interface and a wet growth environment for microbial communities; the adsorption capacity and mass transfer efficiency of the material to volatile organic compounds and peculiar smell molecules are improved, and the buffering capacity of a system for coping with impact loads is effectively enhanced, so that the comprehensive performance and engineering applicability of the waste gas treatment base material are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste gas treatment, in particular to a high-strength porous water-storing waste gas treatment matrix material and a preparation method thereof. BACKGROUND

[0002] At present, in the field of waste gas treatment, adsorption method is widely used due to its high efficiency, but traditional adsorption materials such as activated carbon need to be replaced after adsorption saturation, have high operation cost and produce hazardous waste; in order to overcome these defects, adsorption and biodegradation are combined, among which, the high-strength porous matrix material with microbial carrier and water storage function is beneficial to provide stable attachment points and humid growth environment for microbial community, thereby promoting the continuous degradation of pollutants to realize in-situ recovery of adsorption capacity and improve the long-term operation stability and economy of the treatment system. However, in the prior art, the adsorbent such as activated carbon or bamboo charcoal is simply compounded with biological filler by physical mixing method, which has certain synergistic purification effect, but in terms of structural strength and continuous moisture retention capacity of the matrix material, due to the deficiencies of existing materials in pore structure and water holding performance, it is difficult to maintain stable microbial activity and pollutant mass transfer efficiency in long-term operation. Not only does it reduce the synergistic efficiency of adsorption-biodegradation, but also causes the compaction of filler layer and the increase of resistance, at the same time, it affects the rapid proliferation and metabolic function of microbial community, and also reduces the buffer capacity of the system to respond to impact load, resulting in the need for regular replacement or offline regeneration of the filler, thereby reducing the comprehensive performance and engineering applicability of the high-strength porous water-storing waste gas treatment matrix material.

[0003] Therefore, there is an urgent need for a high-strength porous water-storing waste gas treatment matrix material and a preparation method thereof. SUMMARY

[0004] The present application aims to provide a high-strength porous water-storing waste gas treatment matrix material and a preparation method thereof to solve the problems raised in the background.

[0005] To achieve the above-mentioned purpose, the present application provides a high-strength porous water-storing waste gas treatment matrix material, which comprises the following raw materials: Activated carbon accounts for 5-30wt%; zeolite accounts for 2-25wt%; silicon dioxide accounts for 40-75wt%; calcium sulfate dihydrate accounts for 1-15wt%; calcium oxide accounts for 5-30wt%; aluminum powder accounts for 0.01-0.15wt%; deionized water accounts for 0.2-1wt%; Among them, the calcium oxide reacts with water to generate calcium hydroxide and release heat, and the reaction formula is: At the same time, aluminum powder reacts with calcium hydroxide under alkaline conditions to produce hydrogen gas and form a uniform distribution of microporous structure, and the reaction formula is: ; the calcium sulfate dihydrate is dehydrated into calcium sulfate hemihydrate or anhydrous calcium sulfate under high-temperature and high-pressure curing conditions, and is interwoven with the generated calcium hydroxide and silicon dioxide to form a high-strength skeleton network; the activated carbon and zeolite are embedded in the skeleton network to jointly form a three-dimensional matrix with high porosity, excellent water holding capacity and mechanical strength; and the material has good structural stability and sustained water release characteristics while maintaining low density, thereby providing a stable adhesion interface and humid growth environment for microbial communities.

[0006] In addition, the activated carbon and zeolite are compounded and synergized, which is beneficial to improve the adsorption capacity and mass transfer efficiency of the material for volatile organic compounds; mainly because the activated carbon provides a developed microporous structure for efficient capture of pollutants, and the zeolite selectively adsorbs polar molecules through ion exchange, and the two form complementary adsorption sites in the skeleton network; thereby forming a synergistic effect of physical adsorption and ion exchange to jointly form a high-efficiency pollutant enrichment-conversion interface.

[0007] Preferably, the raw materials include the following mass percentages: The activated carbon accounts for 10-15 wt%; the zeolite accounts for 6-12 wt%; the silicon dioxide accounts for 55-65 wt%; the calcium sulfate dihydrate accounts for 2-7 wt%; the calcium oxide accounts for 10-20 wt%; and the aluminum powder accounts for 0.04-0.9 wt%.

[0008] Secondly, the application provides a preparation method of a high-strength porous water storage type waste gas treatment matrix material, including the following steps: S1, raw material pretreatment: first, the activated carbon is activated, then the zeolite is modified, and then the activated activated carbon, the modified zeolite, the silicon dioxide, the calcium sulfate dihydrate, the calcium oxide and the aluminum powder are respectively dried and crushed to obtain fine powder with a water content of less than 1% and a particle size of 45-75 μm; S2, mixing, stirring and gas evolution reaction: the fine powder is put into a high-speed stirrer, dry mixed at a speed of 300-500 r / min for 10-15 min to obtain a uniform dry mixture, then under the condition of maintaining a stirring speed of 600-800 r / min, deionized water is added at a rate of 5-8 mL / min through a constant-flow pump, after the addition is completed, the stirring speed is adjusted to 400-500 r / min in a closed environment to continue the reaction for 8-12 min, so that the calcium oxide reacts with water to generate calcium hydroxide and release heat, the aluminum powder simultaneously reacts in the alkaline medium to release hydrogen, and a uniformly distributed microporous structure is formed in the system, and by controlling the water addition rate and stirring intensity, the gas is uniformly nucleated and grown inside the slurry, and finally a wet slurry with a three-dimensionally connected microporous structure is formed; S3. Mold casting and static setting: The mold coated with release agent is placed on a vibration table. At a vibration frequency of 25-35Hz, the wet slurry is continuously poured into the mold cavity. Through continuous mechanical vibration for 2-6 minutes, air bubbles trapped inside the slurry are effectively removed, while promoting the dense arrangement of particles and uniform distribution of the liquid phase. The mold after casting is then transferred to a constant temperature and humidity environment of 22-28℃ and 85-95% for static curing for 3-5 hours. This allows the slurry to initially form a gel network with calcium hydroxide, calcium sulfate and silica as the skeleton, resulting in a dense matrix preform with uniformly distributed pores. S4. High-temperature and high-pressure steam curing: The matrix green body is transferred to a high-pressure steam curing kettle and cured by segmented heating and constant pressure to obtain a high-strength porous matrix material with stable three-dimensional channels, high specific surface area and long-lasting water storage and release function. S5. Crushing and Screening: After primary crushing of the high-strength porous matrix material using a jaw crusher, it is transferred to a double roll crusher for fine crushing under the conditions of a roll gap of 5-50mm, a roll speed ratio of 1:1.5, and circulating water cooling. Then, it is graded and screened by a multi-layer vibrating screen to obtain regular particle products with a particle size of 5-50mm.

[0009] Furthermore, in step S1, the activated carbon activation treatment includes the following steps: Activated carbon and a 15-25% nitric acid solution are added to an acid-resistant reactor at a solid-liquid mass ratio of 1:8-1:12. The mixture is stirred continuously in a constant temperature water bath at 75-85℃ for 2-4 hours to allow the nitric acid to fully oxidize and erode the surface and internal pores of the activated carbon, thereby introducing abundant oxygen-containing functional groups onto its surface through strong oxidation. After the reaction is complete, the carbon is repeatedly washed with deionized water until neutral, then placed in a forced-air drying oven and dried at 105-115℃ to constant weight. Subsequently, it is transferred to a tube furnace and heated to 550-650℃ at a heating rate of 8-12℃ / min under nitrogen protection and calcined for 1-2 hours. This process reconstructs the activated carbon framework structure at high temperature, effectively removing blockages (such as amorphous carbon) in the pores, thereby increasing its specific surface area and micropore volume. Finally, activated carbon with a well-developed pore structure, high surface activity, and excellent biocompatibility is obtained.

[0010] Furthermore, in S1, the zeolite used is natural clinoptilolite, which has a regular pore structure and abundant surface acidic sites for the selective adsorption of polar odor molecules.

[0011] Furthermore, in step S1, the zeolite modification treatment includes the following steps: The zeolite particles with a particle size of 0.5-2 mm and a sodium chloride solution with a concentration of 1.0-1.5 mol / L are added into a corrosion-resistant reaction kettle at a solid-liquid mass ratio of 1:5-1:8, and stirring is continuously carried out at 85-95 DEG C and a rotating speed of 120-200 rpm for 4-6 h, so that sodium ions are fully exchanged with cations in the zeolite framework, and the pore structure and surface chemical properties are improved; Then, the obtained material is transferred to a vacuum filtration device for solid-liquid separation, and deionized water at 60-70 DEG C is repeatedly used for washing until no white precipitate is generated in the filtrate detected by using a silver nitrate solution, which indicates that residual chloride ions have been effectively removed; the washed zeolite is treated in a blast drying oven at 110-120 DEG C until a constant weight is obtained, and then is placed in a rare earth cerium chloride solution with a concentration of 0.2-0.5 mol / L, and stirring is carried out at 35-45 DEG C and a rotating speed of 80-120 rpm for 2-4 h, so that rare earth species are fully loaded in the interior and surface of the zeolite pore; Finally, the temperature is programmed to rise to 450-550 DEG C at a temperature rising rate of 2-4 DEG C / min in a muffle furnace, and the temperature is kept at this temperature for 2-3 h, and the modification process of the zeolite is completed.

[0012] Further, in the S4, the method for segmental temperature rising and constant pressure curing comprises the following steps: S4.1, first stage curing: the temperature in the curing kettle is raised to 150-180 DEG C at a temperature rising rate of 8-12 DEG C / min, the pressure is simultaneously adjusted to 0.8-1.2 MPa, and the temperature and pressure conditions are maintained for 3-5 h, so that the calcium sulfate dihydrate is partially dehydrated to convert into calcium sulfate hemihydrate, and the exothermic reaction of calcium oxide and water is excited, and the preliminary crosslinking between active components and the stabilization of microporous structure are promoted; S4.2, second stage curing: the temperature is continuously raised to 190-210 DEG C, the pressure is correspondingly raised to 1.5-2.0 MPa, and the temperature and pressure are kept constant for 2-4 h, so that the calcium silicate hydrate is generated by the reaction of silicon dioxide and calcium hydroxide, and the calcium sulfate anhydride is further converted from the calcium sulfate dihydrate and participates in the formation of ettringite, and a high-strength three-dimensional network structure with the calcium silicate hydrate-ettringite as the skeleton is formed; S4.3, programmed temperature reduction: after the curing is completed, the temperature reduction is carried out at a rate of 5-8 DEG C / min until the temperature in the kettle is reduced to below 50 DEG C, and the accumulation of thermal stress caused by the sudden temperature reduction is effectively relieved, so that the structure of the base material has integrity and long-term stability.

[0013] Compared with the prior art, the present application has the following beneficial effects: 1、The high-strength porous water-storing type exhaust gas treatment matrix material and its preparation method adopt a multi-component synergistic formula of activated carbon, zeolite, silicon dioxide, calcium sulfate dihydrate, calcium oxide and aluminum powder, and through aluminum powder foaming under alkaline conditions and high-temperature high-pressure steam curing technology, the material forms a multi-level pore structure with three-dimensional interconnected pores and high specific surface area; this structure not only maintains the characteristics of low density, but also has good mechanical strength and long-lasting water storage and release functions, which can provide a stable adhesion interface and a humid growing environment for microbial communities; not only improves the adsorption capacity and mass transfer efficiency of the material for volatile organic compounds and odor molecules, but also effectively enhances the buffering capacity of the system to respond to impact load, thereby improving the comprehensive performance and engineering applicability of the high-strength porous water-storing type exhaust gas treatment matrix material.

[0014] 2、The high-strength porous water-storing type exhaust gas treatment matrix material and its preparation method, through mold vibration casting and segmented temperature and pressure control curing method, are beneficial to the removal of bubbles inside the matrix blank and the uniform formation of gel network, not only promoting the crosslinking between active components and the stabilization of microporous structure, but also forming a high-strength three-dimensional network with calcium silicate hydrate and calcium aluminate as the skeleton, so that the material has high porosity and excellent water holding capacity, and improves the structural integrity and long-term stability, thereby making the exhaust gas treatment system reliable and durable under long-term continuous operation conditions. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The preparation method flowchart of the high-strength porous water-storing type exhaust gas treatment matrix material of the present application; Figure 2 The adsorption capacity retention rate line graph of the present application. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0017] Example 1 According to Figure 1As shown, first, 10% of activated carbon, 6% of zeolite, 62.86% of silicon dioxide, 2% of calcium sulfate dihydrate, 18% of calcium oxide, 0.04% of aluminum powder and 1.1% of water were prepared as raw materials; wherein the activated carbon was activated by stirring with 20% nitric acid solution at 80°C for 3h, washed and dried, and then calcined at 600°C for 1.5h under nitrogen protection; the zeolite was natural clinoptilolite, which was modified by ion exchange with 1.2mol / L sodium chloride solution at 90°C for 5h, washed, loaded with 0.3mol / L cerium chloride solution, and calcined at 500°C for 2.5h; after all the raw materials were dried and crushed to a particle size of 45-75μm, they were put into a high-speed stirrer for dry mixing at 400r / min for 12min, then deionized water was added at a rate of 6mL / min under stirring at 600r / min, after the dripping was completed, the reaction was continued in a closed environment at 450r / min for 10min to complete the gas evolution; the obtained wet slurry was poured into a mold coated with a release agent in advance, placed on a 30Hz vibration table to remove bubbles for 4min, then cured at 25°C and 90% humidity for 4h; the green body was moved into a high-pressure steam curing kettle, first heated to 165°C at a rate of 10°C / min, cured at a pressure of 1.0MPa for 4h, then heated to 200°C, cured at a pressure of 1.8MPa for 3h, and finally cooled to below 50°C at a rate of 6°C / min; the cooled substrate was crushed by a jaw crusher and a roller crusher under circulating water cooling, and graded by a vibrating screen to obtain regular granular products with a particle size of 5-50mm.

[0018] Example 2 According to Figure 1As shown, first, 12% of activated carbon, 8% of zeolite, 59.5% of silicon dioxide, 4% of calcium sulfate dihydrate, 15% of calcium oxide, 0.06% of aluminum powder and 1.44% of water are prepared as raw materials; wherein the activated carbon is activated by stirring with 18% nitric acid solution at 78℃ for 3.5h, washed and dried, and then calcined at 580℃ for 2h under nitrogen protection; the zeolite is natural clinoptilolite, which is modified by ion exchange with 1.0mol / L sodium chloride solution at 88℃ for 5.5h, washing, loading 0.4mol / L cerium chloride solution and calcining at 480℃ for 3h; after all the raw materials are dried and crushed to a particle size of 45-75μm, they are put into a high-speed stirrer for dry mixing at 350r / min for 14min, then deionized water is added at a rate of 5.5mL / min under stirring at 700r / min, after dropping, the reaction continues in a closed environment at 480r / min for 9min to complete the gas evolution; the obtained wet slurry is poured into a mold coated with a release agent in advance, placed on a vibration table at 28Hz to vibrate for 5min to remove bubbles, then placed in a 26℃, 88% humidity environment for 4.5h to solidify; the green body is moved into a high-pressure steam curing kettle, first heated to 170℃ at 9℃ / min, pressure 1.1MPa for 3.5h, then heated to 195℃, pressure 1.7MPa for 3.5h, finally programmed to cool to below 50℃ at 5.5℃ / min; the cooled matrix is crushed by a jaw crusher and a roller crusher under circulating water cooling, and graded by a vibrating screen to obtain regular granular products with a particle size of 5-50mm.

[0019] Example 3 According to Figure 1As shown, first, raw materials of 14% activated carbon, 10% zeolite, 55.2% silicon dioxide, 5% calcium sulfate dihydrate, 14.5% calcium oxide, 0.08% aluminum powder and 1.22% water are prepared; wherein the activated carbon is activated by stirring with 22% nitric acid solution at 82℃ for 2.5h, washed and dried, and then calcined at 620℃ for 1h under nitrogen protection; the zeolite is natural clinoptilolite, which is modified by ion exchange with 1.4mol / L sodium chloride solution at 92℃ for 4.5h, washed, loaded with 0.25mol / L cerium chloride solution, and calcined at 520℃ for 2h; after all the raw materials are dried and crushed to a particle size of 45-75μm, they are put into a high-speed stirrer for dry mixing at 450r / min for 11min, then deionized water is added at a rate of 7mL / min under stirring at 750r / min, after the dripping is completed, the reaction is continued in a closed environment at 420r / min for 11min to complete the gas evolution; the obtained wet slurry is poured into a mold coated with a release agent in advance, placed on a vibration table at 32Hz to vibrate for 3min to remove bubbles, and then cured at 27℃ and 92% humidity for 3.5h; the green body is moved into a high-pressure steam curing kettle, first heated to 160℃ at 11℃ / min, cured at a pressure of 0.9MPa for 4.5h, then heated to 205℃, cured at a pressure of 1.9MPa for 2.5h, and finally cooled to below 50℃ at a programmed cooling rate of 7℃ / min; the cooled matrix is crushed by a jaw crusher and a roller crusher under circulating water cooling, and graded by a vibrating screen to obtain regular granular products with a particle size of 5-50mm.

[0020] Example 4 According to Figure 1As shown, first, 15% of activated carbon, 12% of zeolite, 52.35% of silicon dioxide, 7% of calcium sulfate dihydrate, 12% of calcium oxide, 0.09% of aluminum powder and 1.56% of water are prepared as raw materials; wherein, the activated carbon is activated by stirring with 25% nitric acid solution at 85℃ for 2h, washed and dried, and then calcined at 650℃ for 1h under nitrogen protection; the zeolite is modified by ion exchange with 1.5mol / L sodium chloride solution at 95℃ for 4h, washed, loaded with 0.35mol / L cerium chloride solution, and then calcined at 550℃ for 2h; after all the raw materials are dried and crushed to a particle size of 45-75μm, they are put into a high-speed stirrer for dry mixing at 500r / min for 10min, then deionized water is added at a rate of 8mL / min under stirring at 800r / min, after the addition is completed, the reaction is continued at 500r / min for 8min in a closed environment to complete the gas evolution; the obtained wet slurry is poured into a mold precoated with a release agent, placed on a 35Hz vibration table to remove bubbles for 2min, and then cured at 28℃ in a 95% humidity environment for 3h; the green body is moved into a high-pressure steam curing kettle, first heated to 180℃ at a rate of 12℃ / min, cured at a pressure of 1.2MPa for 3h, then heated to 210℃, cured at a pressure of 2.0MPa for 2h, and finally cooled to below 50℃ at a rate of 8℃ / min; the cooled substrate is crushed by a jaw crusher and a roller crusher under circulating water cooling, and graded by a vibrating screen to obtain regular granular products with a particle size of 5-50mm.

[0021] In order to verify that the waste gas treatment matrix material prepared by the embodiment of the present application has good structural stability and water holding and releasing functions, the following test examples are used to illustrate the waste gas treatment matrix material provided by the embodiment of the present application.

[0022] Test Example The purpose of this test group is to explore the influence of different component proportions on the waste gas treatment matrix material, and to detect the compressive strength, porosity, water holding rate, saturated adsorption capacity and cycle stability of the waste gas treatment matrix material of the present application.

[0023] Test Objective: Test Group A, Test Group B, Test Group C and Test Group D respectively use the component proportions of the waste gas treatment matrix materials provided by Examples 1-4; the control examples use Control Group A to Control Group K, which are specifically set as follows: Control Group A The preparation method is exactly the same as that of Example 3, but the raw material ratio is activated carbon 30%, zeolite 25%, silicon dioxide 75%, calcium sulfate dihydrate 15%, calcium oxide 30%, aluminum powder 0.15%, and water 1%.

[0024] Control Group B The preparation method is completely same as example 3, but the raw material ratio is activated carbon 5%, zeolite 2%, silicon dioxide 40%, calcium sulfate dihydrate 1%, calcium oxide 5%, aluminum powder 0.01%, and water 0.2%.

[0025] Control group C The raw material ratio and preparation process are basically same as example 2, except that the activated carbon component is not added, and the silicon dioxide amount is correspondingly increased to 70wt%, and the proportions of the remaining components remain unchanged.

[0026] Control group D The raw material ratio and preparation process are basically same as example 2, except that the zeolite used is a common zeolite with a silicon-aluminum ratio of 2:1, which does not have a regular pore structure and abundant surface acid sites.

[0027] Control group E The raw material ratio and preparation process are basically same as example 2, except that the zeolite component is not added, and the silicon dioxide amount is correspondingly increased to 66wt%, and the proportions of the remaining components remain unchanged.

[0028] Control group F The raw material ratio and preparation process are basically same as example 2, except that the silicon dioxide component is not added, and the activated carbon amount is correspondingly increased to 25wt% and the zeolite amount is correspondingly increased to 15wt%, and the proportions of the remaining components remain unchanged.

[0029] Control group G The raw material ratio and preparation process are basically same as example 1, but the method of staged temperature rise and constant pressure is not used for curing, specifically: the matrix blank is moved to a high-pressure steam curing oven, directly heated to 200℃, the pressure is raised to 1.8MPa, and the temperature and pressure are kept constant for 7h; after curing, the temperature is lowered to below 50℃ at a rate of 6℃ / min, and the matrix material is obtained.

[0030] Control group H The raw material ratio and preparation process are basically same as example 1, except that the mold does not use a vibration table, and the mold coated with a release agent is placed horizontally, and the wet slurry is directly poured into the mold cavity without mechanical vibration, and then transferred to a constant temperature and humidity environment with a temperature of 26℃ and a relative humidity of 88% for solidification for 4.5h, and the matrix blank is obtained.

[0031] Control group I The traditional activated carbon-zeolite mixed material is used as a control: 50% of coal-based granular activated carbon (particle size 4-6mm, iodine value ≥800mg / g) and 50% of natural zeolite (particle size 3-5mm) are physically mixed, and directly used as a biological filter filler after uniform mixing, without any molding and high temperature and high pressure curing process.

[0032] Control group J The conventional ceramic carrier is used as a control: clay, shale and pore-forming agent are used as main raw materials, and the spherical ceramic with a particle size of 5-10 mm is prepared by the steps of batching, mixing, granulating and sintering at 1100 DEG C, the apparent density of the spherical ceramic is 0.9-1.1 g / cm3, the porosity is 35%-40%, and the specific surface area is 2-4 m2 / g.

[0033] Control group K 30% of activated carbon, 20% of diatomite, 15% of kaolin, 10% of cement, 8% of gypsum, 5% of sawdust, 5% of bentonite and 7% of water are uniformly mixed, and then extruded and dried at normal pressure and 80 DEG C for 12 hours to obtain a porous adsorption matrix material.

[0034] Test method: according to the compressive strength, porosity, water retention rate, saturated adsorption capacity and cycle stability of the waste gas treatment matrix material, tests are respectively carried out, and the specific test method is as follows: Compressive strength: a universal material testing machine is used, the sample is processed into a standard cylinder (diameter 50 mm x height 50 mm), an axial pressure is applied at a loading rate of 2 mm / min, and the maximum load at the time of sample failure is recorded; the compressive strength calculation formula is: sigma=F / A, wherein sigma is the compressive strength (MPa), F is the failure load (N), and A is the cross-sectional area of the sample (mm2); Porosity: a mercury intrusion method is used, a full-automatic mercury porosimeter is used, the dry sample is placed in an expansion meter, and the mercury intrusion volume is measured in the pressure range of 0.1-400 MPa; the total porosity calculation formula is: P=(V_p / V_b) x 100%, wherein P is the total porosity (%), V_p is the cumulative mercury intrusion volume (cm3 / g), and V_b is the apparent volume of the sample (cm3 / g); Water retention rate: the dry sample is weighed (W_d) and then completely immersed in deionized water, taken out after 24 hours, wiped with wet gauze to remove surface water, and immediately weighed (W_s); the water retention rate calculation formula is: W_r=[(W_s-W_d) / W_d] x 100%, wherein W_r is the water retention rate (%), W_s is the saturated wet weight (g), and W_d is the dry weight (g); Saturated adsorption capacity: a dynamic adsorption method is used, in a fixed bed adsorption device, a toluene standard gas with a concentration of 1000 mg / m3 is introduced, the gas flow rate is 0.5 L / min, and the adsorption temperature is 25 DEG C; when the outlet concentration reaches 95% of the inlet concentration, it is considered to be saturated adsorption, and the saturated adsorption capacity calculation formula is: Q=(C_0 x V x t) / m, wherein Q is the saturated adsorption capacity (mg / g), C_0 is the inlet concentration (mg / m3), V is the gas flow rate (m3 / min), t is the penetration time (min), and m is the adsorbent mass (g). Cycling stability: the sample was subjected to adsorption-desorption cycle test, after each adsorption saturation, desorption at 105℃ for 2h, after cooling to room temperature, the next adsorption was carried out; the retention rate of saturated adsorption capacity after 20 cycles was used to evaluate the cycling stability, the retention rate calculation formula was: R=(Q_20 / Q_1)×100%, wherein R was the adsorption capacity retention rate (%), Q_20 was the saturated adsorption capacity (mg / g) of the 20th cycle, Q_1 was the saturated adsorption capacity (mg / g) of the 1st cycle.

[0035] The specific detection indexes are shown in Table 1.

[0036] Table 1: Detection indexes of each sample Compressive strength (MPa) Porosity (%) Water retention (%) Toluene saturated adsorption capacity (mg / g) Adsorption capacity retention rate (20 times, %) Test group A 4.8 68.5 152 138 88.5 Test group B 5.2 66.8 148 142 90.1 Test group C 4.9 67.2 150 145 89.3 Test group D 5.1 67.8 151 140 89.8 Control group A 3.1 72.3 160 155 75.2 Control group B 2.5 58.6 125 98 82.4 Control group C 4.5 60.1 135 85 86.7 Control group D 4.7 65.5 142 118 84.5 Control group E 4.8 62.3 138 105 85.9 Control group F 2.8 71.5 145 132 72.1 Control group G 3.3 64.2 140 128 80.5 Control group H 3.6 62.8 132 122 83.2 Control group I Could not be molded - - 156 65.8 Control group J 8.5 38.5 45 28 94.5 Control group K 1.5 52.4 90 95 78.3 According to Table 1 and Figure 2 , the high-strength porous water storage type waste gas treatment matrix material prepared in Examples 1-4 (test groups A-D) of the application exhibits excellent comprehensive performance in terms of compressive strength, porosity, water retention rate, toluene saturated adsorption capacity and cycling stability; in particular, as follows: The adsorption capacity and mass transfer efficiency of the material are improved by the composite ratio and activation modification of activated carbon and zeolite: the toluene saturated adsorption capacity of test group B is 142mg / g, and the capacity retention rate after 20 cycles is 90.1%; in contrast, the control group C (85mg / g, 86.7%) without activated carbon lacks sufficient capture capacity due to the absence of developed microporous structure, and the control group E (105mg / g, 85.9%) without zeolite weakens the selective adsorption of polar molecules due to the lack of ion exchange sites; in addition, the control group D (118mg / g, 84.5%) using ordinary zeolite has insufficient regularity of pore structure and richness of surface acid sites, resulting in decreased adsorption selectivity and easy deactivation of active sites, further proving that the activated carbon and specific structure zeolite activated and modified form a synergistic effect of microporous physical capture and ion exchange adsorption in the composite material, by constructing a complementary adsorption interface, the initial adsorption capacity is improved while the regeneration ability of the adsorption site in the cyclic use is effectively maintained, thereby enhancing the mass transfer efficiency and long-term stability of the material; The compressive strength of the test groups A-D is maintained at 4.8-5.2 MPa, the porosity is between 66.8%-68.5%, and the water holding rate is as high as 148%-152%; while the control group A (strength 3.1 MPa) and the control group B (strength 2.5 MPa, porosity 58.6%) have their component proportions beyond the preferred range, resulting in a too intense or insufficient reaction system, which in turn causes the material skeleton structure to develop unevenly, with some pore channels collapsing or poor connectivity, leading to a significant decrease in mechanical properties and pore characteristics; however, compared with the traditional ceramsite carrier (control group J, porosity 38.5%, water holding rate 45%) or the physical mixed filler (control group I, which cannot be formed), the ratio is still feasible through the idea of building a three-dimensional network by aluminum powder foaming and high temperature and high pressure curing; in addition, the control group G (strength 3.3 MPa, porosity 64.2%) without optimized curing and the control group H (strength 3.6 MPa, porosity 62.8%) without using vibration casting have their internal bubble residues and insufficient particle arrangement density, resulting in an increase in internal defects of the matrix, causing damage to the integrity of the microstructure, proving that the mold vibration casting and segmented temperature and pressure control curing process adopted by the present application is crucial for eliminating internal bubbles of the slurry, promoting close particle arrangement, and forming a uniform and high-strength three-dimensional network with calcium silicate hydrate-calcium aluminate as the skeleton, and is a key guarantee for simultaneously achieving high mechanical strength, excellent pore structure, and long-term water storage function of the material; After 20 adsorption-desorption cycles, the test groups A-D have a retention rate of adsorption capacity of more than 88.5%, with good cycle stability; in contrast, the control group F, which does not add silicon dioxide components, fails to form a calcium silicate hydrate-calcium aluminate skeleton network, resulting in insufficient material structure strength (2.8 MPa), and is prone to skeleton collapse and pore blockage during the cycle process, making the retention rate of adsorption capacity drop to 72.1%; the control group G, which uses a single-stage high temperature and high pressure curing process, has internal thermal stress accumulation leading to microcracks, resulting in damage to the structural integrity, and its retention rate drops to 80.5%; the control group K, which uses a conventional mixed drying process, fails to form a stable three-dimensional crosslinked network, with loose structure and low strength (1.5 MPa), and the structure is easily damaged during the cycle, with a retention rate of only 78.3%; this shows that the present application introduces silicon dioxide to participate in the hydration reaction to build a high-strength skeleton, and uses a segmented temperature and pressure control steam curing process and vibration casting forming technology, effectively relieving the internal stress of the material and reducing the initiation and expansion of microcracks, thereby forming a three-dimensional network with excellent structural integrity and fatigue resistance, improving the structural durability and performance retention rate of the matrix material in long-term adsorption-desorption cycles; In addition, compared with the physical mixed activated carbon-zeolite (control group I, unable to be shaped, poor cycle stability), conventional ceramsite (control group J, high strength but extremely low porosity, water retention and adsorption capacity) and other porous adsorption matrix (control group K, poor performance in all aspects), the material of the present application shows more balanced characteristics in comprehensive performance; specifically, on the basis of maintaining a compressive strength of not less than 4.8 MPa, the porosity of the material is more than 66.8%, the water retention is not less than 148%, the saturated adsorption capacity of methylbenzene is higher than 138 mg / g, and after 20 adsorption-desorption cycles, the adsorption capacity retention rate is still maintained at more than 88.5%; these data show that the material presents positive effects in mechanical stability, porous structure, water retention capacity, pollutant adsorption performance and long-term use stability.

[0037] In summary, the present application prepares a waste gas treatment matrix material with high mechanical strength, ideal pore structure, good water retention and release characteristics, high adsorption capacity and stable cycle performance by the multi-component synergistic formula of activated carbon, zeolite, silicon dioxide, calcium sulfate dihydrate, calcium oxide and aluminum powder, combined with the activation and modification treatment of raw materials, vibration casting molding and the specific process of segmented high temperature and high pressure steam curing; the material shows high mechanical strength, rich pore structure, excellent water retention and release performance, and good pollutant adsorption capacity and cycle stability, can provide a long-term stable adhesion interface and suitable humid growth microenvironment for microbial community, thereby strengthening the synergistic effect of pollutant adsorption enrichment and biodegradation process in the waste gas treatment system, and improving the buffering capacity of the system to respond to waste gas load fluctuations.

[0038] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high-strength porous water-storing exhaust gas treatment matrix material, characterized by, The method comprises the following steps: S1, after the activated carbon is activated and treated, and the zeolite is modified, the activated carbon and the modified zeolite are respectively dried and crushed with silica, calcium sulfate dihydrate, calcium oxide and aluminum powder to obtain fine powder with a water content of less than 1% and a particle size of 45-75 μm; S2, the fine powder is put into a high-speed mixer to mix into a dry mixture, then deionized water is added dropwise, and the reaction is continued to form a wet slurry with a three-dimensional interconnected microporous structure; S3, the mold coated with a release agent is placed on a vibration table, and the wet slurry is continuously poured into the mold cavity under the vibration frequency of 25-35 Hz and mechanical vibration for 2-6 min, and then the slurry is allowed to solidify to form a gel network with calcium hydroxide, calcium sulfate and silicon dioxide as the skeleton, thereby obtaining a matrix body with compact structure and uniform pore distribution; S4, the matrix body is moved to a high-pressure steam curing kettle, and is cured by the method of stepwise heating and constant pressure to obtain a high-strength porous matrix material with stable three-dimensional channels, high specific surface area and persistent water storage and release functions; S5, the high-strength porous matrix material is primary crushed by a jaw crusher, then is finely crushed by a roll crusher, and then is classified and screened by a multi-layer vibrating screen to obtain regular granular products with a particle size of 5-50 mm.

2. The preparation method of the high-strength porous water-storage type waste gas treatment matrix material according to claim 1, characterized in that, In S1, the activated carbon activation treatment comprises the following steps: The activated carbon and a nitric acid solution with a concentration of 15-25% are added to an acid-resistant reaction kettle at a solid-liquid mass ratio of 1:8-1:12, and the nitric acid is continuously stirred in a 75-85°C constant temperature water bath for 2-4 h to allow the nitric acid to fully oxidize and erode the surface and internal channels of the activated carbon; After the reaction is completed, the activated carbon is repeatedly washed with deionized water until it is neutral, and then is dried in a forced air drying oven at 105-115°C until the weight is constant, and then is transferred to a tube furnace and heated to 550-650°C at a heating rate of 8-12°C / min under nitrogen protection, and is calcined for 1-2 h to allow the activated carbon skeleton structure to be reconstructed at high temperature to form activated carbon with developed pore structure, high surface activity and excellent biological affinity.

3. The preparation method of the high-strength porous water-storage type waste gas treatment matrix material according to claim 1, characterized in that, In S1, the zeolite is natural clinoptilolite, which has a regular pore structure and rich surface acid sites for selective adsorption of polar odor molecules.

4. The preparation method of the high-strength porous water-storage type waste gas treatment matrix material according to claim 1, characterized in that, In S1, the zeolite modification treatment comprises the following steps: Zeolite particles with a particle size of 0.5-2 mm and a sodium chloride solution with a concentration of 1.0-1.5 mol / L are added to a corrosion-resistant reaction kettle at a solid-liquid mass ratio of 1:5-1:8, and the sodium ions are fully exchanged with the cations in the zeolite skeleton by continuously stirring at a speed of 120-200 rpm at 85-95°C for 4-6 h; Subsequently, the obtained material is transferred to a vacuum filtration device for solid-liquid separation, and deionized water at 60-70 ℃ is repeatedly washed until no white precipitate is generated in the filtrate detected by silver nitrate solution; the washed zeolite is treated in a 110-120 ℃ air drying oven until the weight is constant, and then is placed in a rare earth cerium chloride solution with a concentration of 0.2-0.5 mol / L, and is stirred at a speed of 80-120 rpm at 35-45 ℃ for 2-4 h, so that the rare earth species is fully loaded in the internal and surface of the zeolite pores; Finally, the temperature is programmed to rise to 450-550 ℃ at a rate of 2-4 ℃ / min in a muffle furnace, and is kept at this temperature for 2-3 h to complete the modification process of the zeolite.

5. The method for preparing the high-strength porous water-storage type waste gas treatment matrix material according to claim 1, characterized in that, In the S2, the high-speed blender is used to dry mix the fine powder for 10-15 min at a speed of 300-500 r / min.

6. The method of claim 1, wherein the high-strength porous water- storing exhaust gas treatment substrate material is prepared by the steps of: preparing a porous ceramic substrate; and coating the porous ceramic substrate with a coating solution comprising a water-soluble polymer, a water-soluble binder, and a water-soluble pore-forming agent. In the S2, the deionized water is added dropwise by a constant flow pump at a rate of 5-8 mL / min, while the high-speed blender maintains a stirring speed of 600-800 r / min; after the dropwise addition is completed, the reaction is continued in a closed environment at 400-500 r / min for 8-12 min.

7. The method of claim 1, wherein the high-strength porous water- storing exhaust gas treatment substrate material is prepared by the steps of: preparing a porous ceramic substrate; and coating the porous ceramic substrate with a coating solution comprising a water-soluble polymer, a water-soluble binder, and a water-soluble pore-forming agent. In the S3, the standing curing is carried out in a constant temperature and humidity environment with a temperature of 22-28 ℃ and a relative humidity of 85-95% for 3-5 h.

8. The method of claim 1, wherein the high-strength porous water- storing exhaust gas treatment substrate material is prepared by the steps of: preparing a porous ceramic substrate; and coating the porous ceramic substrate with a coating solution comprising a water-soluble polymer, a water-soluble binder, and a water-soluble pore-forming agent. In the S5, the roll crusher is used to finely crush under the conditions of a roll gap distance of 5-50 mm, a roll speed ratio of 1:1.5, and circulating water cooling.

9. A high-strength porous water-storing exhaust gas treatment substrate material prepared by the method of any one of claims 1 to 8, characterized by The raw materials include: active carbon accounts for 5-30 wt%; zeolite accounts for 2-25 wt%; silicon dioxide accounts for 40-75 wt%; calcium sulfate dihydrate accounts for 1-15 wt%; calcium oxide accounts for 5-30 wt%; aluminum powder accounts for 0.01-0.15 wt%; deionized water accounts for 0.2-1 wt%; The calcium oxide reacts with water to generate calcium hydroxide and release heat, and the aluminum powder reacts with the calcium hydroxide under alkaline conditions to generate hydrogen gas, forming a uniformly distributed microporous structure; the calcium sulfate dihydrate is dehydrated into semi-water or anhydrous calcium sulfate under high temperature and pressure curing conditions, and is interwoven with the generated calcium hydroxide and silicon dioxide, forming a high-strength skeleton network; the active carbon and zeolite are embedded in the skeleton network, together forming a three-dimensional matrix with high porosity, excellent water holding capacity and mechanical strength.

10. The high-strength porous water-storing exhaust gas treatment matrix material according to claim 9, characterized in that, The raw materials preferably have the following mass percentages: active carbon accounts for 10-15 wt%; zeolite accounts for 6-12 wt%; silicon dioxide accounts for 55-65 wt%; calcium sulfate dihydrate accounts for 2-7 wt%; calcium oxide accounts for 10-20 wt%; aluminum powder accounts for 0.04-0.9 wt%; deionized water accounts for 0.4-0.7 wt%.

Images