阅读说明：本技术 一种CPAM改性SiO2/CaSiO3材料的制备方法及应用 (CPAM modified SiO2/CaSiO3Preparation method and application of material ) 是由 温华辉 于 2020-08-12 设计创作，主要内容包括：本发明属于环保技术领域,具体涉及一种CPAM改性SiO<Sub>2</Sub>/CaSiO<Sub>3</Sub>材料的制备方法及应用。该制备方法的步骤包括：先用四水硝酸钙和九水偏硅酸钠为原料制备硅酸钙粉末,然后用硅酸钙和正硅酸四乙酯通过与十六烷基三甲基溴化铵和氨水等在不同条件下反应、陈化,最后煅烧得到SiO<Sub>2</Sub>/CaSiO<Sub>3</Sub>粉末；随后将SiO<Sub>2</Sub>/CaSiO<Sub>3</Sub>粉末浸于阳离子聚丙烯酰胺水溶液中,获得CPAM改性SiO<Sub>2</Sub>/CaSiO<Sub>3</Sub>。本发明制备的材料可用于微塑料的去除,可以彻底的去除水中的微塑料。(The invention belongs to the technical field of environmental protection, and particularly relates to CPAM modified SiO 2 /CaSiO 3 A preparation method and application of the material. The preparation method comprises the following steps: firstly, calcium silicate powder is prepared by using calcium nitrate tetrahydrate and sodium metasilicate nonahydrate as raw materials, then the calcium silicate and tetraethyl orthosilicate are reacted and aged with hexadecyl trimethyl ammonium bromide, ammonia water and the like under different conditions, and finally SiO is obtained by calcining 2 /CaSiO 3 Powder; followed by the formation of SiO 2 /CaSiO 3 Soaking the powder in cationic polyacrylamide aqueous solution to obtain CPAM modified SiO 2 /CaSiO 3 . The material prepared by the invention can be used for removing micro-plastics and can be used for removing micro-plasticsTo completely remove the micro plastic in the water.)

1. CPAM modified SiO₂/CaSiO₃The preparation method of the material is characterized by comprising the following steps:

the method comprises the following steps: adding calcium nitrate tetrahydrate into deionized water, stirring for 60-90min to completely dissolve the calcium nitrate tetrahydrate, adding a mixture A consisting of fatty alcohol-polyoxyethylene ether, sodium dodecyl sulfate and F127 in a certain proportion into a water bath at 45-55 ℃, and slowly stirring for 2-3h to form gel; then, dripping a sodium metasilicate nonahydrate solution into the gel in a water bath at the temperature of 60-65 ℃, continuously stirring for 3-5h, aging the product for 24-36h at normal temperature, washing with deionized water, standing in absolute ethyl alcohol for 18-24h, drying the product for 12-15h in a vacuum drying oven at the temperature of 40-50 ℃, and grinding to obtain calcium silicate powder;

step two: adding calcium silicate powder, tetraethyl orthosilicate and hexadecyl trimethyl ammonium bromide into 100ml of absolute ethyl alcohol-deionized water solution, stirring for 30-40min at normal temperature, then adding a proper amount of ammonia water into the solution, and stirring for 2-3h in water bath at 40-50 ℃; then centrifuging the solution to obtain sol, and aging the sol for 36-48h at room temperature; drying the product in an oven at 80-90 ℃ after aging, grinding the dried product and calcining the product in a muffle furnace at 680-700 ℃ for 3-4h to obtain SiO₂/CaSiO₃Powder;

step three: mixing SiO₂/CaSiO₃The powder is centrifugally washed by absolute ethyl alcohol and deionized water, and then is placed in 50ml of cationic polyacrylamide aqueous solution with certain concentration and stirred in water bath at 50-55 ℃ for 6-8h to obtain CPAM modified SiO₂/CaSiO₃A material;

in the first step, the mass ratio of the calcium nitrate tetrahydrate to the sodium metasilicate nonahydrate is 1:1-1: 1.2; the mass ratio of the calcium nitrate tetrahydrate to the mixture A is 15:1-20: 1; the mass ratio of the fatty alcohol-polyoxyethylene ether, the lauryl sodium sulfate and the F127 in the mixture A is (2.5-3) to 4 (1.1-1.8); in the second step, the molar ratio of the calcium silicate powder to the ethyl orthosilicate is 3.2:1-5.75:1, the mass ratio of the ethyl orthosilicate to the hexadecyl trimethyl ammonium bromide is 80:1-120:1, and the volume ratio of the anhydrous ethanol to the deionized water is 30:1-40: 1.

2. CPAM-modified SiO according to claim 1₂/CaSiO₃The preparation method of the material is characterized in that the amount of the substance of the calcium nitrate tetrahydrate in the step one is 0.07-0.1 mol; the volume of the ammonia water in the second step is 2-4 ml; in the third step, the concentration of the cationic polyacrylamide aqueous solution is 0.8 wt%, and the molecular weight of the cationic polyacrylamide is 1200 ten thousand.

3. CPAM-modified SiO according to claim 1₂/CaSiO₃The preparation method of the material is characterized in that in the first step, the concentration of the calcium nitrate tetrahydrate is 0.2-0.33g/ml after the calcium nitrate tetrahydrate is dissolved in deionized water; the concentration of the sodium metasilicate nonahydrate solution was 0.5 g/ml.

4. CPAM modified SiO according to any of claims 1 to 3₂/CaSiO₃The application of the material prepared by the preparation method of the material in removing the micro-plastics in sewage is characterized in that the micro-plastics in the water body are removed in a targeted manner, and the removal rate is high; the method comprises the following specific steps:

adding 1g of CPAM modified SiO into every 10L of sewage to be treated₂/CaSiO₃Stirring the materials for 1-2h, standing for 6-8h, and filtering the sewage by using a filter screen to remove the micro-plastics in the sewage.

Technical Field

The invention belongs to the technical field of environmental protection, and particularly relates to CPAM modified SiO₂/CaSiO₃A preparation method and application of the material.

Background

The concept of micro-plastics was first proposed in 2004 by foreign scholars, and specifically defined to mean plastic chips and particles with a diameter of 5 mm. The micro plastic has the problems of wide pollution range and great potential environmental pollution, and has great harm in the environment. The first is the adsorption of the micro-plastic to other pollutants in the environment; it has an extremely high adsorption capacity due to its higher specific surface area, whereas persistent organic pollutants and the hydrophobic nature of microplastics, which are already widely distributed in the existing environment, make them more prone to aggregation. Secondly, the harm of the micro-plastic to organisms; the micro-plastics have similar size and density to low nutritional levels of marine organisms such as plankton, and are therefore susceptible to being miseaten by marine organisms. After the low-end food chain is biologically eaten, the micro-plastics and the organic pollutants adsorbed by the micro-plastics cannot be digested, and the micro-plastics and the organic pollutants are enriched to the last time of the biological chain and finally enter a human body.

As micro plastic is used as a new pollutant, the existing sewage treatment does not specially aim at the pollutant, so even after the sewage treatment with more strict treatment requirements on heavy metal ions, the remaining amount of the micro plastic is still 10-25 percent; in the treatment process with lower requirements, the retention amount is higher and can reach more than 60%.

Disclosure of Invention

In order to solve the problem of low removal rate of the micro-plastic in sewage treatment, the invention provides a preparation method and application of a cationic polyacrylamide modified silicon dioxide/calcium silicate material, which can effectively remove the micro-plastic in a water body.

In order to achieve the purpose, the invention adopts the following technical scheme: CPAM modified SiO₂/CaSiO₃The preparation method of the material comprises the following steps:

the method comprises the following steps: adding a certain amount of calcium nitrate tetrahydrate into deionized water, stirring for 60-90min to completely dissolve the calcium nitrate tetrahydrate, and then adding a mixture A consisting of fatty alcohol-polyoxyethylene ether, sodium dodecyl sulfate and F127 in a certain proportion into the deionized water in a water bath at 45-55 ℃ to slowly stir for 2-3h to form gel. Then, a proper amount of sodium metasilicate nonahydrate solution is dripped into the gel in a water bath at the temperature of 60-65 ℃, the mixture is continuously stirred for 3-5h, the product is aged for 24-36h at normal temperature, then is washed by deionized water and is placed in absolute ethyl alcohol for 18-24h, and then the product is dried for 12-15h in a vacuum drying oven at the temperature of 40-50 ℃, and is ground to obtain calcium silicate powder after being dried.

Step two: adding a certain amount of calcium silicate powder, tetraethyl orthosilicate and hexadecyl trimethyl ammonium bromide into 100ml of absolute ethyl alcohol-deionized water solution, stirring for 30-40min at normal temperature, then adding a proper amount of ammonia water into the solution, and stirring for 2-3h in water bath at 40-50 ℃. Then centrifuging the solution to obtain sol, and aging the sol for 36-48h at room temperature; aging the productDrying in an oven at 80-90 ℃, grinding the dried product and calcining in a muffle furnace at 680-700 ℃ for 3-4h to obtain SiO₂/CaSiO₃And (3) powder.

Step three: mixing SiO₂/CaSiO₃The powder is centrifugally washed by absolute ethyl alcohol and deionized water, and then is placed in 50ml of cationic polyacrylamide aqueous solution with certain concentration and stirred in water bath at 50-55 ℃ for 6-8h to obtain CPAM modified SiO₂/CaSiO₃A material.

The amount of the substance of the calcium nitrate tetrahydrate in the step one is 0.07mol-0.1 mol; the mass ratio of the calcium nitrate tetrahydrate to the sodium metasilicate nonahydrate is 1:1-1: 1.2; the mass ratio of the calcium nitrate tetrahydrate to the mixture A is 15:1-20: 1; the mass ratio of the fatty alcohol-polyoxyethylene ether, the lauryl sodium sulfate and the F127 in the mixture A is (2.5-3) to (4) (1.1-1.8).

The volume of the ammonia water added in the second step is 2-4 ml; the molar ratio of the calcium silicate powder to the ethyl orthosilicate is 3.2:1-5.75:1, the mass ratio of the ethyl orthosilicate to the hexadecyl trimethyl ammonium bromide is 80:1-120:1, and the volume ratio of the anhydrous ethanol to the deionized water is 30:1-40: 1.

In the third step, the concentration of the cationic polyacrylamide aqueous solution is 0.8 wt%, and the molecular weight of the cationic polyacrylamide is 1200 ten thousand.

Preferably, the concentration of the calcium nitrate tetrahydrate in the deionized water in the step one is 0.2-0.33 g/ml; the concentration of the sodium metasilicate nonahydrate solution was 0.5 g/ml.

The invention also provides CPAM modified SiO₂/CaSiO₃The material is applied to removing micro-plastics in water, and 1g of CPAM modified SiO is added into every 10L of sewage to be treated₂/CaSiO₃Stirring the materials for 1-2h, standing for 6-8h, and filtering the sewage by using a filter screen to remove the micro-plastics in the sewage.

Has the advantages that: the invention provides CPAM modified SiO₂/CaSiO₃The preparation method and the application of the material effectively solve the problem of high residual rate of the micro-plastic in sewage treatment in the prior art, and the invention uses SiO₂/CaSiO₃The preparation of the composite material increases the pores and the specific surface area of the composite materialThe adsorption capacity is effectively improved; meanwhile, the composite material has excellent hydrophobic property by synthesizing the silicon dioxide on the surface of the calcium silicate, so that the material is easier to disperse and uniform in sewage on one hand, and the attraction of the composite material to the micro plastic with hydrophobic property is improved on the other hand. To SiO₂/CaSiO₃The cationic polyacrylamide modification of (2) enables the surface of the material to be grafted with CPAM with various functional groups, which enables the composite material to have extremely high removal capability on different micro plastics such as PP, PE and the like.

Drawings

FIG. 1 is a scanning electron microscope photograph of the product of example 1 of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.