阅读说明：本技术 一种易再生的亚甲基蓝吸附剂的制备方法 (Preparation method of easily-regenerated methylene blue adsorbent ) 是由 谢宇风 田亚铭 邓苗 刘朋 邓建雄 熊维威 于 2021-09-15 设计创作，主要内容包括：本发明提供了一种易再生的亚甲基蓝吸附剂的制备方法,包括高岭土,以及复合在所述高岭土表面的焦磷酸铜材料等。本发明将焦磷酸铜与高岭土进行复合,形成稳定复合结构,得到一种可重复使用的对亚甲基蓝具有优异吸附性能的焦磷酸铜/高岭土复合材料,当材料吸附亚甲基蓝至饱和后,通过添加双氧水对吸附的亚甲基蓝进行催化降解后再生,并且再生后的材料吸附性能良好。本发明的优点是材料具有制备简单、可反复利用、环境友好、成本低、可大量生产的特点,显示了较高的经济效益和环境效益。(The invention provides a preparation method of an easily-regenerated methylene blue adsorbent, which comprises kaolin, a copper pyrophosphate material compounded on the surface of the kaolin and the like. According to the invention, copper pyrophosphate and kaolin are compounded to form a stable composite structure, so that the reusable copper pyrophosphate/kaolin composite material with excellent adsorption property to methylene blue is obtained, when the methylene blue is adsorbed to saturation, hydrogen peroxide is added to perform catalytic degradation on the adsorbed methylene blue, and then the regenerated material is good in adsorption property. The invention has the advantages that the material has the characteristics of simple preparation, repeated utilization, environmental friendliness, low cost and mass production, and shows higher economic benefit and environmental benefit.)

1. The preparation method of the methylene blue adsorbent easy to regenerate is characterized by comprising the following steps:

step 1: weighing copper sulfate pentahydrate powder and ammonium dihydrogen phosphate powder according to a molar ratio of 1:1, respectively adding deionized water, ultrasonically stirring for dissolving, mixing the two dissolved solutions, stirring for complete reaction, and dropwise adding nitric acid until the solution is clear to obtain a mixed solution A;

step 2: stirring and mixing the mixed solution A and kaolin at room temperature to obtain a mixed solution B;

and step 3: and (3) drying and crushing the mixed solution B obtained in the step (2), carrying out heat treatment, and crushing and grinding the material after the material is cooled to room temperature to obtain the methylene blue adsorbent easy to regenerate.

2. The preparation method according to claim 1, wherein the solution A in the step 1 is dispersed by ultrasonic stirring, the ultrasonic frequency is 20-60 Hz, and the dispersion time is 5-10 min.

3. The preparation method according to claim 1, wherein the solution A in the step 1 is a solution dropwise added with 65-68% nitric acid until the precipitate disappears.

4. The preparation method according to claim 1, wherein the kaolin in the step 2 has a particle size of 50 to 200 meshes.

5. The preparation method according to claim 1, wherein the mass ratio of the kaolin to the generated copper pyrophosphate in the step 2 is 5:1 to 3: 1.

6. The preparation method according to claim 1, wherein the stirring in the step 2 is magnetic stirring, and the stirring time is 60-180 min.

7. The method according to claim 1, wherein the drying time in step 3 is 4-24 hours, and the drying temperature is 40-120 ℃.

8. The preparation method according to claim 1, wherein the heat treatment temperature in step 3 is 400 to 600 ℃, the holding time is 60 to 180min, and the temperature rise rate is 1 to 10 ℃/min.

Technical Field

The invention relates to the technical field of dye wastewater treatment, in particular to a methylene blue adsorbent and a preparation method thereof.

Background

Kaolin is a non-metallic mineral, a clay and claystone based on clay minerals of the kaolinite group. The pure kaolin is in a white, fine and soft soil shape and has good physical and chemical properties such as plasticity, fire resistance and the like. Kaolin has wide application, is mainly used for paper making, ceramics and refractory materials, is used for coating, rubber filler, enamel glaze and white cement raw materials, and is used for industrial departments such as plastics, paint, pigment, grinding wheels, pencils, daily cosmetics, soap, pesticide, medicine, textile, petroleum, chemical industry, building materials, national defense and the like in a small amount.

The dye wastewater is the main industrial wastewater which is difficult to treat and has considerable harm to the environment at present in China, a large amount of dye wastewater is generated in China every year, the dye wastewater has a long retention period in the environment, and is easy to be highly enriched in organisms, so that long-term adverse effects are generated on the health of human beings. Methylene blue is a common basic dye, and wastewater of the methylene blue has the characteristics of high organic matter concentration, large chromaticity, large water quality change, high biological toxicity, difficult degradation and the like, and is difficult to effectively treat.

The traditional dye wastewater treatment process can be roughly divided into the following steps: physical, chemical and biological methods, the currently used treatment methods have certain limitations, for example, the chemical method can generate sludge which is difficult to treat; although the biological method has lower operation cost, the dye wastewater can not be completely decolorized, and the biological method has toxic and side effects on microorganisms. The adsorption method is a physical and chemical method, has a simpler technical process and has certain advantages in the field of dye wastewater treatment.

The traditional adsorbents for treating dyes mainly comprise carbon materials, alumina, molecular sieves, resins and the like, but the adsorbents have limited adsorption capacity and slow adsorption rate, and after the adsorbents are used, the adsorbents with saturated adsorption can cause serious secondary pollution to the environment if the adsorbents cannot be effectively treated in time. Therefore, how to find an adsorbent which can solve the problem of treatment and disposal of dye wastewater, can be effectively regenerated and reused, prolongs the service life of the dye wastewater, has the characteristics of low investment, short period, simple and convenient operation, safety, small change of pH value in the production process and the like, and becomes one of important problems to be solved urgently in various manufacturers and downstream application fields.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide an easily regenerated methylene blue adsorbent and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

step 1: weighing copper sulfate pentahydrate powder and ammonium dihydrogen phosphate powder according to a molar ratio of 1:1, respectively adding deionized water, ultrasonically stirring for dissolving, mixing the two dissolved solutions, stirring for complete reaction, and dropwise adding nitric acid until the solution is clear to obtain a mixed solution A;

step 2: stirring and mixing the mixed solution A and kaolin at room temperature to obtain a mixed solution B;

and step 3: drying and crushing the mixed solution B obtained in the step 2, carrying out heat treatment, and crushing and grinding the material after the material is cooled to room temperature to obtain the methylene blue adsorbent which is easy to regenerate;

further, the copper sulfate pentahydrate powder and ammonium dihydrogen phosphate powder in the step 1 are preferably copper sulfate pentahydrate powder and ammonium dihydrogen phosphate powder;

further, the solution A in the step 1 is a solution which is subjected to ultrasonic stirring and dispersion, the ultrasonic frequency is 20-60 Hz, and the dispersion time is 5-10 min;

further, the solution A in the step 1 is a solution dropwise added with 65-68% nitric acid until the precipitate disappears;

preferably, the particle size of the kaolin in the step 2 is 50-200 meshes;

further, the mass ratio of the kaolin to the generated copper pyrophosphate in the step 2 is 5: 1-3: 1;

further, the stirring in the step 2 is magnetic stirring, and the stirring time is 30-180 min;

further, in the step 3, the drying time is 4-24 hours, and the drying temperature is 40-120 ℃;

further, in the step 3, the heat treatment temperature is 400-600 ℃, the heat preservation time is 60-180 min, and the heating rate is 1-10 ℃/min;

the invention has the beneficial effects that:

1. the raw materials used for preparing the adsorbent are wide in source and low in price, the preparation method of the adsorbent is simple and feasible in process, convenient to operate and stable in structure, belongs to resource recycling, is non-toxic to the environment, is suitable for large-scale industrial production, and has good adsorption performance, easy degradation and high recycling rate.

2. After the copper pyrophosphate/kaolinite composite material adsorbent prepared by the invention is adsorbed and saturated, copper pyrophosphate is used as an effective catalyst for degrading methylene blue dye, so that the adsorbed methylene blue dye is quickly degraded and the regeneration of an adsorbing material is realized, the adsorbed methylene blue is prevented from becoming a pollution source again, the material is adsorbed and degraded for multiple times, the service life of the adsorbent is prolonged, the effects of reducing the cost and changing waste into valuable are achieved, and remarkable social benefits and environmental benefits are certainly realized.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is an X-ray powder diffraction pattern of the adsorbent prepared in example 1.

FIG. 2 is an SEM photograph of an adsorbent prepared in example 1.

FIG. 3 is a graph showing the change in the removal rate with the number of times of adsorption in example 1.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1:

step 1: weighing 1.659g of copper sulfate pentahydrate powder and 0.764g of ammonium dihydrogen phosphate powder respectively, adding 40ml of deionized water, performing ultrasonic dispersion for 10min until the materials are fully dissolved, mixing the dissolved copper sulfate pentahydrate solution and the dissolved ammonium dihydrogen phosphate solution in pairs, after precipitation, dropwise adding 4ml of nitric acid, and stirring by using a glass rod until the solution is clear to obtain a mixed solution A;

step 2: weighing 5g of kaolin of 100 meshes, stirring the kaolin and the mixed solution A for 120min at room temperature, and placing the mixture in an oven for drying for 5 h;

and step 3: and crushing the dried material, placing the crushed material in a muffle furnace for heat treatment, keeping the roasting temperature at 550 ℃ for 3h, taking out the crushed material after the temperature of the material is reduced to the room temperature, crushing and grinding the crushed material to obtain the methylene blue adsorbent easy to regenerate.

To verify the performance of the adsorbent prepared in example 1 above, the following experiment was performed:

and (3) detecting the adsorption performance of the adsorbent before regeneration:

respectively placing 0.4g of the methylene blue adsorbent prepared in the embodiment into beakers, adding 50mL of methylene blue solution with the initial concentration of 20mg/L, performing an adsorption experiment on a magnetic stirrer at the rotating speed of 200r/min for 2h, and measuring the adsorption effect of the adsorbent on the methylene blue before regeneration;

regeneration test

The used methylene blue adsorbent is regenerated by the following method, the adsorbent material which is saturated in adsorption is collected, 50ml of distilled water is measured by a measuring cylinder, and the distilled water is poured into a beaker where the adsorbent is located. Adjusting the temperature of a constant-temperature water bath heating pot to 40 ℃, heating and insulating materials in a beaker, measuring 2ml of hydrogen peroxide by using a liquid transfer gun after the temperature is stable, adding the hydrogen peroxide into the beaker, magnetically stirring for 4 hours for catalysis, collecting an adsorbent after the catalysis is finished, adding deionized water for repeated washing, and drying to constant weight to obtain a regenerated methylene blue adsorbent;

adsorbent adsorption performance detection after regeneration

Adding 50ml of methylene blue solution with the initial concentration of 20mg/L into the regenerated adsorbent, performing magnetic stirring for 2 hours to perform an adsorption experiment, and measuring the adsorption effect of the regenerated adsorbent on the methylene blue;

the adsorption performance of the methylene blue adsorbent before and after regeneration is shown in fig. 3.

The results show that: the removal rate of the methylene blue adsorbent prepared in the embodiment 1 of the invention before regeneration reaches 97.33%, and the removal rates of the adsorption effects of the adsorbent after regeneration are all more than 92%. Comprehensive evaluation shows that the methylene blue adsorbent before and after regeneration in the embodiment 1 of the invention keeps good adsorption performance, the regenerated adsorbent can be obtained while degrading the methylene blue dye after the adsorbent is saturated, and the regenerated adsorbent has good adsorption performance and stable adsorption performance, so that the methylene blue adsorbent can be repeatedly used.

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