Solid waste-based granite adsorption filter material and preparation method thereof

Abstract

The invention relates to the field of solid wastes, and particularly discloses a solid-waste-based granite adsorption filter material and a preparation method thereof. A preparation method of a solid waste-based granite adsorption filter material comprises the following steps: S1, granite pretreatment: performing acid activation, grinding, washing, sieving and drying on granite saw mud to obtain an adsorption filter material base material; s2, triple modification: sequentially carrying out precursor modification, alcohol replacement modification, surfactant modification and oscillation on the adsorption filter material base material to obtain a modified adsorption filter material base material; s3, chitosan compounding: blending the modified adsorption filter material base material with chitosan, and reacting to obtain the solid waste-based granite adsorption filter material. The granite saw mud is used as a raw material, waste resources can be fully utilized and subjected to precursor modification, alcohol replacement modification, surfactant modification and chitosan compounding, and the adsorption effect of the adsorption filter material on polluting ions in a water body is remarkably improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of solid waste, and in particular to a solid waste-based granite adsorption filter material and a preparation method thereof. BACKGROUND

[0002] Porous adsorption filter material, as an important functional material, plays a crucial role in many key fields such as environmental protection and chemical industry in today's society. With the increasing emphasis on environmental protection and resource-efficient utilization worldwide, porous adsorption filter material has been increasingly widely applied due to its simple preparation process, good chemical stability and strong resistance. In the field of environmental protection, it can effectively remove harmful substances such as heavy metal ions and organic pollutants in wastewater, greatly improving water quality and providing a strong guarantee for the sustainable use of water resources. In the field of waste gas purification, it can adsorb harmful gases and particulate matters in the air, reducing air pollution and protecting people's health and the ecological environment. In the field of chemical industry, it can be used for the separation and purification of compounds, improving the purity and quality of products, thereby improving production efficiency and reducing production cost. Its application not only promotes the vigorous development of environmental protection, but also brings higher economic and social benefits to the chemical industry, and has extremely significant utilization value and broad market prospect. In addition, in the food, pharmaceutical and other industries, porous adsorption filter material also plays a key role in the refining and purification process of products, further expanding its application range and influence.

[0003] In the preparation of adsorption filter material, municipal sludge, general industrial solid waste (fly ash) and the like are often used as the base material. For municipal sludge, it is usually first subjected to dewatering treatment to remove most of the water therein, so as to reduce the difficulty and energy consumption of subsequent treatment. Then, drying operation is performed to make the sludge reach a certain degree of dryness. Then, a series of complex treatment steps such as sintering are performed to make it have certain adsorption performance. This treatment method requires the cooperation of multiple links, and the process parameters of each link need to be strictly controlled to ensure the quality of the final product. For general industrial solid waste (fly ash), physical modification or chemical modification methods are used. In terms of physical modification, high-temperature calcination is used to change the internal structure and physical properties of fly ash by treating it at high temperature, thereby improving its adsorption capacity. Chemical modification uses acid and alkali treatment and the like to introduce new functional groups or change the surface properties by chemical reaction between acid and alkali and the components in fly ash, thereby enhancing its adsorption performance. These methods can prepare filter material with adsorption function to some extent, meeting the needs of some fields. In addition, some other base materials and preparation methods have also been tried in practical applications, such as using biomass waste to prepare adsorption filter material by pyrolysis, activation and the like to make it have adsorption performance.

[0004] However, the adsorption filter material using municipal sludge and general industrial solid waste as the base material has obvious defects. The preparation of such adsorption filter material consumes a large amount of energy, such as dehydration, drying and sintering, which consumes a large amount of electric power and heat energy, thereby increasing the production cost. At the same time, the preparation process emits a large amount of pollutants such as waste gas and waste residue, which causes great pressure on the environment. Moreover, the purification treatment has poor versatility, and it is difficult to meet the purification needs of different types of pollutants. For some wastewater or waste gas with complex components, the purification effect is often not ideal. Later, granite was used as the adsorption filter material, which alleviated the problems of high preparation cost and high emission during the preparation process, but the adsorption capacity of the granite adsorption filter material still has a lot of room for improvement, and the saturated adsorption capacity is insufficient, which cannot meet the application scenarios with high requirements on the adsorption performance, thereby limiting its wide application in more fields. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a solid waste-based granite adsorption filter material and a preparation method thereof.

[0006] In a first aspect, the present application provides a preparation method of a solid waste-based granite adsorption filter material, comprising the following steps: S1. Granite pretreatment: acid activation, grinding, washing, passing through a 325 mesh sieve, and drying the granite saw mud to obtain an adsorption filter base material; S2. Triple modification: sequentially subjecting the adsorption filter base material to precursor modification, alcohol replacement modification, and surfactant modification, and then oscillating to obtain a modified adsorption filter base material; S3. Chitosan compounding: blending the modified adsorption filter base material with chitosan, adding a crosslinking agent and an initiator, and then reacting under the protection of inert gas and at a temperature of 55-65℃ for 8-9h, cooling, filtering, and drying to obtain a solid waste-based granite adsorption filter material.

[0007] Optionally, in S2, the precursor modification is specifically as follows: Blending dimethyl sulfoxide and the adsorption filter base material at a weight ratio of 10:1, stirring and reacting at a temperature of 80℃ for 3h, washing, centrifuging, and vacuum drying at a temperature of 50℃ after cooling to room temperature.

[0008] Optionally, in S2, the alcohol replacement modification is specifically as follows: Blending the material obtained after the precursor modification with methanol at a weight ratio of 1:1, stirring, adding hydrochloric acid dropwise, then reacting at a temperature of 120℃ for 1h, cooling to room temperature, alcohol washing, centrifuging, and vacuum drying at a temperature of 50℃.

[0009] Optionally, in S2, the surfactant modification is specifically as follows: The material obtained after alcohol substitution modification was blended with a surfactant at a weight ratio of 1:5, reacted at 100°C for 30 hours, and then cooled to room temperature.

[0010] By adopting the above technical solution, the granite material used in this application is granite sawdust, a waste generated during granite processing. During machining processes such as cutting and grinding, the granite surface is cut into fine particles by water and mortar, forming water-containing dust and slurry, which is solid waste with extremely low conventional utilization value. Furthermore, compared to other types of granite materials such as granite gravel, granite sawdust has a higher specific surface area and more exposed active sites. Therefore, this application first performs acid activation on it, dissolving impurities in the granite sawdust and further expanding its internal pore structure. After acid activation, it is washed, sieved, and dried to obtain the adsorption filter material substrate. Subsequently, this application modified the adsorption filter material substrate using the precursor dimethyl sulfoxide (DMSO). The surface hydroxyl groups of silicate minerals (such as quartz and feldspar) in the granite combined with DMSO molecules. The S=O groups in DMSO formed hydrogen bonds with the surface hydroxyl groups of the adsorption filter material substrate, enhancing the polarity between the pores within the granite. Therefore, this application further blended it with methanol. Methanol entered the highly polar interlayer domain through a dynamic displacement reaction, successfully replacing the pores. At this point, the hydrophobicity between the pores within the granite was effectively improved. Immediately afterward, this application introduced a surfactant, successfully performing surfactant modification. This series of treatments resulted in optimal activation of the surface groups of the modified adsorption filter material substrate. Next, this application blended the modified adsorption filter material substrate with chitosan for free radical polymerization. The two formed a three-dimensional network structure and produced a strong synergistic adsorption effect. The resulting solid waste-based granite adsorption filter material exhibited a significant adsorption effect on pollutant ions in water.

[0011] Preferably, the acid activation of S1 specifically involves: Immerse the granite sawdust in H + The mixture is treated in a 15-20% mixed acid solution at a temperature of 50-60℃ and a pressure of 0.5-1.5MPa for 1.5-2 hours. The mixed acid includes hydrofluoric acid, sulfuric acid and nitric acid in a molar ratio of 1:(0.5-0.8):1.

[0012] By adopting the technical scheme, the granite sawing mud is treated with a mixed acid solution of a specific concentration under specific temperature and pressure conditions for a specific time for acid activation, so that impurities in the granite sawing mud are dissolved, and the internal pore structure is further expanded, thereby providing a better substrate for subsequent preparation of solid waste-based granite adsorption filter material with good adsorption effect.

[0013] Preferably, in the surface active agent modification in S2, the surface active agent used is any one of dioctadecyldimethylammonium chloride, hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride.

[0014] Preferably, the surface active agent is dioctadecyldimethylammonium chloride.

[0015] By adopting the technical scheme, the surface groups of the modified adsorption filter material substrate are activated by using any one of dioctadecyldimethylammonium chloride, hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride as the surface active agent, and according to experimental data, when dioctadecyldimethylammonium chloride is used as the surface active agent, the modified adsorption filter material substrate with the highest surface group activity can be obtained, so that the adsorption capacity of the solid waste-based granite adsorption filter material is maximized.

[0016] Preferably, in S2, the oscillation frequency is 20-35 kHz, and the oscillation time is 55-70 min.

[0017] Preferably, the oscillation frequency is 22-28 kHz.

[0018] Preferably, the oscillation time is 60-65 min.

[0019] By adopting the technical scheme, the oscillation time is optimized to 60-65 min, and the oscillation frequency is optimized to 22-28 kHz, so that the modified adsorption filter material substrate can realize full mixing and reaction of components after triple modification, further improve the activation effect of the surface groups of the modified adsorption filter material substrate, and enable the modified adsorption filter material substrate and chitosan to better form a three-dimensional network structure when they are blended, thereby enhancing the synergistic adsorption effect of the two, and significantly improving the adsorption effect of the solid waste-based granite adsorption filter material on the polluting ions in the water body.

[0020] Preferably, in S3, the weight ratio of the modified adsorption filter material substrate to chitosan is 10:(4-10).

[0021] Preferably, in the S3, the weight ratio of the modified adsorption filter material substrate and chitosan is 10:8.

[0022] By adopting the above technical solution, the weight ratio of the modified adsorption filter material substrate and chitosan is controlled, so that the adsorption effect of the solid waste-based granite adsorption filter on the polluting ions in the water body is further optimized, and according to the experimental data, when the weight ratio of the modified adsorption filter material substrate and chitosan is 10:8, the adsorption effect of the solid waste-based granite adsorption filter on the polluting ions in the water body is optimal. If the weight ratio of the modified adsorption filter material substrate and chitosan is less than 10:10, the amount of chitosan is too large, the excess chitosan molecular chains are intertwined with each other, the pores of the granite are blocked, the contact area between the pollutants and the active sites is reduced, and when the amount of chitosan is excessive, the positively charged amino groups of the chitosan may hinder the pollutants from approaching the adsorption sites due to electrostatic repulsion. If the weight ratio of the modified adsorption filter material substrate and chitosan is greater than 10:4, the amount of chitosan is too small, which will result in that the active sites covered on the surface of the granite are limited and cannot fully combine with the pollutants, and the low-concentration chitosan is easy to form local aggregation on the surface of the granite, resulting in that the modified layer is not uniform, part of the area is still exposed to the unmodified surface, and the overall adsorption efficiency is reduced. In the second aspect, the application provides a solid waste-based granite adsorption filter prepared by the above preparation method.

[0023] By adopting the above technical solution, the application uses granite saw mud as a raw material to prepare an adsorption filter, which alleviates the problems of high preparation cost and high emission in the preparation process of the adsorption filter; acid activation dissolves the impurities in the granite saw mud and expands the pore structure; precursor modification enhances the polarity of the internal pores of the granite; alcohol replacement modification enhances hydrophobicity; surfactant modification optimally activates the surface groups; the modified adsorption filter material substrate and chitosan are blended to form a three-dimensional network structure and produce a synergistic adsorption effect, so that the adsorption effect of the adsorption filter on the polluting ions in the water body is significantly improved.

[0024] In summary, the application has the following beneficial technical effects: 1. The application uses granite saw mud as a raw material, which is a waste produced in the process of granite processing and has very low conventional utilization value. The use of the material in the preparation of an adsorption filter can fully utilize waste resources and effectively alleviate the problems of high preparation cost and high emission in the preparation process of the adsorption filter. 2. The application performs acid activation, washing, sieving, drying and other pretreatments on the granite saw mud. Acid activation can dissolve the impurities in the granite saw mud and further expand the internal pore structure. The subsequent washing, sieving and drying operations can obtain a more pure adsorption filter material substrate suitable for subsequent processing. 3. The application is modified by a precursor, the surface hydroxyl groups of silicate minerals in granite are combined with dimethyl sulfoxide molecules, the polarity between the internal pores of granite is enhanced; then alcohol replacement modification is carried out, methanol enters the interlayer domain with high polarity through dynamic displacement reaction, the hydrophobicity between the internal pores of granite is improved; then surfactant modification is carried out, the surface groups of the modified adsorption filter substrate are optimally activated; finally, it is compounded with chitosan, and the two form a three-dimensional network structure and produce a strong synergistic adsorption effect, which can significantly improve the adsorption effect of the adsorption filter on the polluted ions in water. DETAILED DESCRIPTION

[0025] Material sources The raw materials used in the application are commercially available products, except for special instructions, which are as follows: Granite saw mud, after detection, it is found that the water content is 0.75%, the liquid limit is 27.4%, the plastic limit is 24.44%, the plasticity index is 2.96, the pH value is 8.2, and the specific surface area is 317.4 m 2 / kg.

[0026] The application will be further described in detail in combination with examples and comparative examples.

[0027] Example 1.1 A preparation method of a solid waste-based granite adsorption filter, comprising the following steps: S1. Granite pretreatment: immerse the granite saw mud in a 15wt% hydrofluoric acid solution, and treat it under the conditions of a temperature of 50℃ and a pressure of 1.5MPa for 1.5h, for acid activation, grind, wash with deionized water, pass through a 325 mesh sieve, and dry to constant weight to obtain an adsorption filter substrate; S2. Triple modification: 9.1 L of dimethyl sulfoxide was dispersed in 1 L of water, 1 kg of adsorption filter substrate was added after stirring for 10 min at room temperature, and the precursor modification was carried out by stirring at a temperature of 80°C for 3 h. After cooling to room temperature, it was washed, centrifuged, vacuum dried at a temperature of 50°C, ground, and sieved through a 325 mesh sieve; the material obtained after the precursor modification, methanol, and aluminum chloride were blended in a weight ratio of 1:1:0.125, and after stirring, 38 wt% of hydrochloric acid was added dropwise, the amount of hydrochloric acid being 60 wt% of the material obtained after the precursor modification, and then the reaction was carried out at a temperature of 120°C for 1 h. After cooling to room temperature, it was alcohol washed, centrifuged, vacuum dried at a temperature of 50°C, ground, and sieved through a 325 mesh sieve; a surfactant (cetyltrimethylammonium chloride) was dispersed in methanol to obtain a 1 mol / L surfactant solution, and then the material obtained after the alcohol replacement modification was immersed in the surfactant solution in a weight ratio of 1:5, and after pre-stirring for 20 min, the surfactant modification was carried out by stirring at a temperature of 100°C for 30 h. After cooling to room temperature, the material obtained after the surfactant modification was placed in an ultrasonic shaker, and after oscillation at a frequency of 20 kHz for 70 min, the oscillation was repeated 3 times. After taking out, washing, centrifuging, and vacuum drying to a constant weight, it was ground and sieved through a 150 mesh sieve to obtain a modified adsorption filter substrate. S3. Chitosan complexation: The modified adsorption filter substrate and chitosan were blended in a weight ratio of 10:10, and then water was added and stirred for 30 min. Then, a crosslinking agent, methylene bisacrylamide, and an initiator, ammonium persulfate, were added, the amount of methylene bisacrylamide being 50 wt% of the modified adsorption filter substrate, and the amount of ammonium persulfate being 25 wt% of the modified adsorption filter substrate. After stirring for 5 min, the reaction was carried out under the protection of nitrogen at a temperature of 65°C for 8 h. After cooling to room temperature, it was filtered, washed, vacuum dried to a constant weight, ground, and sieved through a 150 mesh sieve (0.1 mm) to obtain a solid waste-based granite adsorption filter.

[0028] Example 1.2 A method for preparing a solid waste-based granite adsorption filter, comprising the following steps: S1. Granite pretreatment: The granite sawing mud was immersed in a 15 wt% hydrofluoric acid solution, and the acid activation was carried out at a temperature of 60°C and a pressure of 0.5 MPa for 2 h. After deionized water washing and sieving through a 325 mesh sieve, it was dried to a constant weight to obtain an adsorption filter substrate. S2. Triple modification: 9.1 L dimethyl sulfoxide was dispersed in 1 L water, 1 kg adsorption filter substrate was added after stirring for 10 min at room temperature, and the precursor modification was carried out by stirring at a temperature of 80 DEG C for 3 h, and after cooling to room temperature, it was washed, centrifuged, vacuum dried at a temperature of 50 DEG C, ground, and sieved through a 325 mesh screen; the material obtained after the precursor modification, methanol and aluminum chloride were blended in a weight ratio of 1:1:0.125, stirred and then dropped into 38 wt% hydrochloric acid, the amount of hydrochloric acid was 60 wt% of the material obtained after the precursor modification, and then reacted at a temperature of 120 DEG C for 1 h, cooled to room temperature, alcohol washed, centrifuged, vacuum dried at a temperature of 50 DEG C, ground, and sieved through a 325 mesh screen; the surfactant (hexadecyl trimethyl ammonium chloride) was dispersed in methanol to obtain a 1 mol / L surfactant solution, and then the material obtained after the alcohol replacement modification was immersed in the surfactant solution in a weight ratio of 1:5, pre-stirred for 20 min, and then surfactant modified at a temperature of 100 DEG C for 30 h, and cooled to room temperature; the material obtained after the surfactant modification was placed in an ultrasonic shaker, oscillated at a frequency of 35 kHz for 55 min, repeated for 3 cycles, taken out, washed, centrifuged, vacuum dried to constant weight, ground, and sieved through a 150 mesh screen to obtain the modified adsorption filter substrate; S3. Chitosan complexation: the modified adsorption filter substrate and chitosan were blended in a weight ratio of 10:4, water was added and stirred for 30 min, and then the crosslinking agent methylene bisacrylamide and the initiator ammonium persulfate were added, the amount of methylene bisacrylamide was 50 wt% of the modified adsorption filter substrate, and the amount of ammonium persulfate was 25 wt% of the modified adsorption filter substrate, and then the reaction was carried out under the protection of nitrogen at a temperature of 55 DEG C for 9 h, and after cooling to room temperature, it was filtered, washed, vacuum dried to constant weight, ground, and sieved through a 150 mesh screen to obtain the solid waste-based granite adsorption filter.

[0029] Example 2.1 A method for preparing a solid waste-based granite adsorption filter, which is different from example 1.1 in that in the acid activation of S1, a mixed acid is used, specifically: 1:0.5:1 molar ratio of hydrofluoric acid, sulfuric acid and nitric acid are blended, and then diluted with water to H + Concentration is 15wt%, a mixed acid solution is obtained, and then the granite saw mud is immersed in the mixed acid solution, and the rest is the same as example 1.1.

[0030] Example 2.2 A method for preparing a solid waste-based granite adsorption filter, which is different from example 1.1 in that in the acid activation of S1, a mixed acid is used, specifically: 1:0.8:1 molar ratio of hydrofluoric acid, sulfuric acid and nitric acid are blended, and then diluted with water to H +The concentration of the mixed acid solution is 20wt%, and then the granite sawing mud is immersed in the mixed acid solution, and the rest is the same as example 1.1.

[0031] Example 2.3 A preparation method of a solid waste-based granite adsorption filter material, which is different from example 1.1 in that a mixed acid is used in the acid activation of S1, specifically: hydrogen fluoride, sulfuric acid and nitric acid with a molar ratio of 1:0.2:1 are blended, and then water is added to dilute the H + The concentration of the mixed acid solution is 15wt%, and then the granite sawing mud is immersed in the mixed acid solution, and the rest is the same as example 1.1.

[0032] Example 2.4 A preparation method of a solid waste-based granite adsorption filter material, which is different from example 1.1 in that a mixed acid is used in the acid activation of S1, specifically: hydrogen fluoride, sulfuric acid and nitric acid with a molar ratio of 1:1:1 are blended, and then water is added to dilute the H + The concentration of the mixed acid solution is 15wt%, and then the granite sawing mud is immersed in the mixed acid solution, and the rest is the same as example 1.1.

[0033] Example 3.1 A preparation method of a solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S2, all the cetyltrimethylammonium chloride is replaced by dioctadecyl dimethyl ammonium chloride, and the rest is the same as example 1.1.

[0034] Example 3.2 A preparation method of a solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S2, all the cetyltrimethylammonium chloride is replaced by dioctadecyl dimethyl ammonium chloride, and the rest is the same as example 1.1.

[0035] Example 4.1 A preparation method of a solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S2, the material obtained after modification of the surfactant is placed in an ultrasonic oscillator, and oscillated at a frequency of 22kHz for 65min, and the rest is the same as example 1.1.

[0036] Example 4.2 A preparation method of a solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S2, the material obtained after modification of the surfactant is placed in an ultrasonic oscillator, and oscillated at a frequency of 28kHz for 60min, and the rest is the same as example 1.1.

[0037] Example 5.1 A preparation method of solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S3, the modified adsorption filter material substrate and chitosan are blended according to a weight ratio of 10:6, and the rest is the same as example 1.1.

[0038] Example 5.2 A preparation method of solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S3, the modified adsorption filter material substrate and chitosan are blended according to a weight ratio of 10:8, and the rest is the same as example 1.1.

[0039] Example 5.3 A preparation method of solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S3, the modified adsorption filter material substrate and chitosan are blended according to a weight ratio of 10:15, and the rest is the same as example 1.1.

[0040] Example 5.4 A preparation method of solid waste-based granite adsorption filter material, which is different from example 1.1 in that in S3, the modified adsorption filter material substrate and chitosan are blended according to a weight ratio of 10:2, and the rest is the same as example 1.1.

[0041] Comparative example 1 The granite saw mud was immersed in a 15wt% hydrofluoric acid solution, and was treated for 2h under the conditions of a temperature of 60℃ and a pressure of 0.5MPa for acid activation, was ground, washed with deionized water, and was sieved through a 325 mesh screen after drying to a constant weight, to obtain a solid waste-based granite adsorption filter material.

[0042] Comparative example 2 S1. Granite pretreatment: The granite saw mud was immersed in a 15wt% hydrofluoric acid solution, and was treated for 2h under the conditions of a temperature of 60℃ and a pressure of 0.5MPa for acid activation, was ground, washed with deionized water, and was sieved through a 325 mesh screen after drying to a constant weight, to obtain an adsorption filter material substrate; S2. Triple modification: 9.1 L of dimethyl sulfoxide was dispersed in 1 L of water, 1 kg of adsorbed filter substrate was added after stirring for 10 min at room temperature, and the precursor modification was carried out by stirring at a temperature of 80°C for 3 h, and after cooling to room temperature, it was washed, centrifuged, and vacuum dried at a temperature of 50°C, ground, and sieved through a 325 mesh sieve; the material obtained after the precursor modification, methanol, and aluminum chloride were blended in a weight ratio of 1:1:0.125, and after stirring, 38 wt% of hydrochloric acid was added dropwise, the amount of hydrochloric acid was 60 wt% of the material obtained after the precursor modification, and then the reaction was carried out at a temperature of 120°C for 1 h, and after cooling to room temperature, it was alcohol washed, centrifuged, vacuum dried at a temperature of 50°C, ground, and sieved through a 325 mesh sieve; a surfactant (cetyltrimethylammonium chloride) was dispersed in methanol to obtain a 1 mol / L surfactant solution, and then the material obtained after the alcohol replacement modification was immersed in the surfactant solution in a weight ratio of 1:5, and after pre-stirring for 20 min, the surfactant modification was carried out by stirring at a temperature of 100°C for 30 h, and after cooling to room temperature, the material obtained after the surfactant modification was placed in an ultrasonic shaker, and after oscillation at a frequency of 35 kHz for 55 min, the oscillation was repeated 3 times, and then the material was taken out, washed, centrifuged, vacuum dried to a constant weight, ground, and sieved through a 150 mesh sieve to obtain a solid waste-based granite adsorbed filter material.

[0043] Performance detection The solid waste-based granite adsorbed filter material was dispersed in simulated lead wastewater (lead ion concentration 80 mg / L) until the amount of solid waste-based granite adsorbed filter material added was 0.3 g / L, and a simulated adsorption test was carried out for 100 min under the conditions of a temperature of 25°C and pH = 6, and the residual lead ion concentration in the simulated lead wastewater was determined by inductively coupled plasma mass spectrometry, and the Pb 2+ adsorption rate under the 100 min adsorption experiment was calculated, and the simulated adsorption test was continued to 240 min, and after the lead ion concentration was observed to be stable, the saturated adsorption amount (mg / g) of the solid waste-based granite adsorbed filter material was calculated.

[0044] Table 1 data recording table Group 100 min Pb 2+ Adsorption %]] Saturation adsorption capacity (mg / g) Example 1.1 90.5 151.8 Example 1.2 90.3 151.5 Example 2.1 91.9 155.2 Example 2.2 91.6 155.7 Example 2.3 90.8 152.3 Example 2.4 90.7 152.0 Example 3.1 92.3 154.8 Example 3.2 90.1 151.9 Example 4.1 92.5 165.2 Example 4.2 92.6 164.8 Example 5.1 90.6 152.2 Example 5.2 93.2 166.3 Example 5.3 89.1 149.5 Example 5.4 88.7 146.8 Comparative Example 1 49.7 83.8 Comparative Example 2 64.9 109.2 Data analysis: As can be seen from Table 1, the solid waste-based granite adsorbed filter material obtained in Examples 1.1-1.2 has a Pb 2+ adsorption rate of 90.3-90.5% in the 100 min simulated adsorption test, and a saturated adsorption amount of 151.5-151.8 mg / g in 240 min, while the solid waste-based granite adsorbed filter material in Comparative Example 1 has a Pb 2+The adsorption rate was only 49.7%, and the saturated adsorption capacity after 240 minutes was 83.8 mg / g. The solid waste-based granite adsorption filter media in Comparative Example 2 showed a significantly lower adsorption rate for Pb. 2+ The adsorption rate was only 64.9%, and the saturated adsorption capacity after 240 minutes was 109.2 mg / g. This indicates that the present application modified the adsorption filter material substrate using the precursor dimethyl sulfoxide (DMSO). The surface hydroxyl groups of silicate minerals (such as quartz and feldspar) in the granite combined with DMSO molecules, and the S=O groups in DMSO formed hydrogen bonds with the surface hydroxyl groups of the adsorption filter material substrate, enhancing the polarity between the pores within the granite. Therefore, the present application further blended it with methanol. Methanol entered the highly polar interlayer domain through a dynamic displacement reaction, successfully carrying out the displacement. At this point, the hydrophobicity between the pores within the granite was effectively improved. Then, the present application immediately introduced a surfactant, successfully performing surfactant modification. This series of treatments resulted in optimal activation of the surface groups of the modified adsorption filter material substrate. Next, the present application blended the modified adsorption filter material substrate with chitosan for free radical polymerization, forming a three-dimensional network structure and generating a strong synergistic adsorption effect. The resulting solid waste-based granite adsorption filter material exhibited a significant adsorption effect on pollutant ions in water.

[0045] In Examples 2.1-2.4, this application uses a mixed acid for treatment during acid activation in S1. The results show that the adsorption rate and saturated adsorption capacity of Examples 2.1-2.2 are significantly improved compared to Example 1.1, while the adsorption rate and saturated adsorption capacity of Examples 2.1-2.2 show no significant change compared to Example 1.1. It can be seen that the mixed acid treatment in this application can reduce the amount of hydrofluoric acid used, reduce the toxicity risk, and shorten the treatment time compared to a single acid. Furthermore, the hydrofluoric acid in the mixed acid can first remove metal impurities such as iron and aluminum, while the sulfuric acid can promote the penetration of hydrofluoric acid and enhance the etching effect on dense parts, and the nitric acid can decompose organic pollutants while inhibiting excessive corrosion by hydrofluoric acid.

[0046] In Examples 3.1-3.2, the type of surfactant was changed. The results showed that the adsorption rate and saturated adsorption capacity of Example 3.1 were significantly improved compared with Example 1.1, while the adsorption rate and saturated adsorption capacity of Example 3.2 did not change significantly compared with Example 1.1. It can be seen that when bis(octadecyldimethylammonium chloride) is used as a surfactant, the modified adsorption filter material with the highest surface group activity can be obtained, thereby enabling the adsorption capacity of solid waste-based granite adsorption filter material to reach the maximum value.

[0047] The results of Examples 4.1-4.2 show that the adsorption rate and the saturated adsorption capacity of Examples 4.1-4.2 are greatly improved compared with Example 1.1, which indicates that the optimization of the oscillation time to 60-65 min and the optimization of the oscillation frequency to 22-28 kHz can make the modified adsorption filter substrate realize the effect of full mixing and reaction of each component after the triple modification, further improve the activation effect of the surface groups of the modified adsorption filter substrate, and make the modified adsorption filter substrate and chitosan better form a three-dimensional network structure when they are blended, thereby enhancing the synergistic adsorption effect of the two and significantly improving the adsorption effect of the solid waste-based granite adsorption filter on the polluting ions in the water body.

[0048] In Examples 5.1-5.4, the amount of chitosan is changed, and the results show that the adsorption rate and the saturated adsorption capacity of Example 5.2 are greatly improved compared with Example 1.1, but Example 5.1 has no obvious improvement compared with Example 1.1, and the adsorption rate and the saturated adsorption capacity of Examples 5.3-5.4 still decrease to a certain extent compared with Example 1.1, which indicates that the weight ratio of the modified adsorption filter substrate and chitosan is controlled to further optimize the adsorption effect of the solid waste-based granite adsorption filter on the polluting ions in the water body, and according to the experimental data, it can be known that the adsorption effect of the solid waste-based granite adsorption filter on the polluting ions in the water body is optimal when the weight ratio of the modified adsorption filter substrate and chitosan is 10:8. If the weight ratio of the modified adsorption filter substrate and chitosan is less than 10:10, the amount of chitosan is too large, the excess chitosan molecular chains are intertwined with each other, the pores of the granite are blocked, the contact area of the pollutants and the active sites is reduced, and when the amount of chitosan is excessive, the positively charged amino groups of chitosan may hinder the pollutants from approaching the adsorption sites due to the electrostatic repulsion; if the weight ratio of the modified adsorption filter substrate and chitosan is greater than 10:4, the amount of chitosan is too small, which will result in that the active sites covered on the surface of the granite are limited and cannot fully combine with the pollutants, and the low-concentration chitosan is easy to form local aggregation on the surface of the granite, resulting in that the modified layer is not uniform and part of the area is still exposed to the unmodified surface, thereby reducing the overall adsorption efficiency.

[0049] The examples of the specific embodiment are the preferred examples of the present application, and do not limit the protection scope of the present application, so that: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for preparing solid waste-based granite adsorption filter media, characterized in that, Includes the following steps: S1. Granite pretreatment: The granite sawdust is acid-activated, ground, washed, passed through a 325-mesh sieve, and dried to obtain the adsorption filter material substrate. S2. Triple modification: The adsorption filter material substrate is sequentially modified by precursor, alcohol replacement, surfactant, and shaken to obtain the modified adsorption filter material substrate. S3. Chitosan composite: The modified adsorption filter material substrate and chitosan are blended, and a crosslinking agent and an initiator are added. The mixture is then reacted for 8-9 hours under inert gas protection and at a temperature of 55-65℃. After cooling, filtration, and drying, solid waste-based granite adsorption filter material is obtained.

2. The method for preparing a solid waste-based granite adsorption filter material according to claim 1, characterized in that, The acid activation of S1 specifically involves: Immerse the granite sawdust in H + The mixture is treated in a 15-20% mixed acid solution at a temperature of 50-60℃ and a pressure of 0.5-1.5MPa for 1.5-2 hours. The mixed acid includes hydrofluoric acid, sulfuric acid and nitric acid in a molar ratio of 1:(0.5-0.8):

1.

3. The method for preparing a solid waste-based granite adsorption filter media according to claim 1, characterized in that, In the surfactant modification in S2, the surfactant used is any one of bis(octadecyldimethylammonium chloride), hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.

4. The method for preparing a solid waste-based granite adsorption filter material according to claim 3, characterized in that, The surfactant is dioctadecyldimethylammonium chloride.

5. The method for preparing a solid waste-based granite adsorption filter media according to claim 1, characterized in that, In S2, the oscillation frequency is 20-35kHz and the oscillation time is 55-70min.

6. The method for preparing a solid waste-based granite adsorption filter media according to claim 5, characterized in that, The oscillation frequency is 22-28kHz.

7. The method for preparing a solid waste-based granite adsorption filter media according to claim 6, characterized in that, The oscillation time is 60-65 minutes.

8. The method for preparing a solid waste-based granite adsorption filter media according to claim 1, characterized in that, In step S3, the weight ratio of the modified adsorption filter material substrate to chitosan is 10:(4-10).

9. The method for preparing a solid waste-based granite adsorption filter media according to claim 8, characterized in that, In step S3, the weight ratio of the modified adsorption filter material substrate to chitosan is 10:

8.

10. A solid waste-based granite adsorption filter media prepared by the method of any one of claims 1-9.