CN115779864A - A kind of preparation method and application of reusable sludge-peanut shell activated carbon material - Google Patents

Abstract

The invention discloses a preparation method of a reusable sludge-peanut shell activated carbon adsorbent, which comprises the following steps: respectively drying the residual sludge and the peanut shells, crushing, fully mixing the obtained crushed material with ultrapure water, transferring the mixture into a reaction kettle, carrying out hydrothermal reaction for 10 hours at 260 ℃, cleaning a lower-layer substance by using HCl after the reaction kettle is cooled, and then repeatedly cleaning by using deionized water until a precipitate is neutral; drying the product and then using ZnCl ₂ Soaking in the solution for 10h, and drying; the resulting dry product was placed in a tube furnace N ₂ Calcining in atmosphere and then mixing with absorbent cottonPutting the sludge and the peanut shells into deionized water, mechanically stirring the mixture for 48 hours, and then drying the mixture overnight to obtain the fixed sludge-peanut shell activated carbon. The method takes the excess sludge and the peanut shells as raw materials to prepare the activated carbon adsorbent, and further carries out immobilization treatment on the powder adsorbent, so that the efficient separation and recovery of the adsorbent after use are realized, and the method has excellent recycling performance.

Description

A kind of preparation method of reusable sludge-peanut shell activated carbon material and its application

technical field

The invention belongs to the technical field of environmental protection, and relates to a preparation method and application of a reusable sludge-peanut shell activated carbon material.

Background technique

As emerging environmental pollutants, antibiotics are difficult to eliminate by traditional sewage treatment processes, which pose potential risks to aquatic organisms and ecosystems, and ultimately pose a threat to public health. Therefore, in recent years, the research on antibiotic pollution control technology has become a difficult and hot topic at home and abroad, and activated carbon has attracted extensive attention from researchers because of its good adsorption effect on pollutants in water.

With the rapid development of the water treatment industry, the amount of residual sludge generated during the treatment process has also increased significantly. Since the excess sludge has the characteristics of loose structure, rich organic matter, high water content, and toxic and harmful substances, it needs to be treated in an effective way. At present, the recycling of sludge has become one of the important methods of sludge treatment and disposal. In addition, peanuts are widely planted crops in my country. During the processing and utilization of peanuts, a large number of by-products of peanut shells will be produced. Since peanut shells are rich in crude fibers, they can be carbonized to prepare activated carbon adsorbents. Activated carbon adsorbent is prepared by using surplus sludge and discarded peanut shells, which is used to remove antibiotics in water bodies, which not only realizes the resource utilization of waste, but also solves the problem of antibiotic pollution in water bodies, and realizes "pollution control with waste" . However, most of the existing biochar materials are in powder form, and the separation and recovery efficiency from the water medium after wastewater treatment is low, and may even cause secondary pollution problems.

Contents of the invention

In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a preparation method and application of a reusable sludge-peanut shell activated carbon material. The material prepared by this method can not only effectively remove antibiotics in water, but also realize The high-efficiency separation and recovery of materials after use also prevents the agglomeration of material particles and ensures its removal performance for antibiotics.

A kind of preparation method of reusable sludge-peanut shell activated carbon material comprises the steps:

Step 1. Dry and crush the remaining sludge from the urban sewage treatment plant to obtain crushed sludge; wash the peanut shells to remove impurities, dry and pulverize them to obtain crushed peanut shells; crush the crushed sludge and peanut shells The materials are mixed to obtain a granular mixture;

Step 2. Mix the particle mixture obtained in the above step 1 with ultrapure water and transfer it to the reactor for hydrothermal reaction. After the reactor is cooled, wash the obtained lower precipitate with 1moL/L HCl, and then use deionized Wash with water several times until the sediment is neutral;

Step 3, drying the neutral product obtained in the above step ₂ , soaking it in a ZnCl solution with a mass concentration of 40% for 10 hours, and then drying it overnight at 90-110°C;

Step 4, the product that above-mentioned step 3 is obtained is calcined in tubular furnace _N under atmosphere, obtains powdered carbon black sludge-peanut shell activated carbon;

Step 5. Put the powdered product obtained in the above step 4 together with absorbent cotton in deionized water, mechanically stir for 48 hours, and then dry overnight at 90-110° C. to obtain fixed sludge-peanut shell activated carbon.

Preferably, the mass ratio of crushed sludge to crushed peanut shells in the mixed granular matter in step 1 is 9-5:1-5.

Preferably, the calcination temperature in the step 4 is 800-1000° C., and the calcination time is 90 minutes.

Preferably, the mass ratio of the powdered adsorbent to the absorbent cotton in the fifth step is 1:10-40.

The invention discloses the preparation steps of the easily recyclable sludge-peanut shell adsorbent and its application in treating antibiotic waste water. In the invention, the fixed sludge-peanut shell adsorbent is added into simulated waste water containing antibiotics, and the reaction is carried out under normal temperature and pressure conditions, and the removal of antibiotics can be completed in a relatively short time.

The beneficial effects of the present invention are:

1. The fixed sludge-peanut shell activated carbon adsorbent prepared by the present invention has an adsorption capacity of 238.75mg/g to amoxicillin after testing.

2. The present invention uses excess sludge, peanut shells and other wastes as raw materials to prepare activated carbon adsorbents, which are used to remove antibiotics in water bodies, and realize "pollution control with waste", which meets the requirements of sustainable development.

3. In the present invention, the sludge-peanut shell activated carbon adsorbent is fixed in the absorbent cotton, which realizes the efficient separation and recovery of the adsorbent after use, and also prevents the agglomeration of the adsorbent, which is conducive to the effective adsorption of the activated carbon adsorbent for antibiotics to make full use of site.

4. The fixed sludge-peanut shell activated carbon adsorbent prepared by the present invention can still remove more than 85% of amoxicillin in the water body after five consecutive repeated operations, indicating that the adsorbent prepared by the present invention has excellent The reusability has the potential to be put into practical application.

Description of drawings

Fig. 1 is the removal rate curve of amoxicillin to the adsorbent prepared by the embodiment of the present invention and comparative example;

Fig. 2 is the SEM image of the adsorbent prepared by the embodiment of the present invention and comparative example;

Fig. 3 is the repeated performance test curve of removing amoxicillin by the fixed sludge-peanut shell activated carbon adsorbent prepared in the present invention.

Detailed ways

Example:

A kind of preparation method of easily recyclable sludge-peanut shell activated carbon material comprises the steps:

Step 1. Dry and crush the remaining sludge from the urban sewage treatment plant to obtain crushed sludge; wash the peanut shells to remove impurities, dry and pulverize them to obtain crushed peanut shells; and obtain crushed sludge Mix with crushed peanut shell material in a mass ratio of 7:3 to obtain a granular mixture;

Step 2. Mix the particle mixture obtained in the above step 1 with ultrapure water and transfer it to the reactor for hydrothermal reaction. After the reactor is cooled, wash the obtained lower precipitate with 1moL/L HCl, and then use deionized Wash with water several times until the sediment is neutral;

Step 3, drying the neutral product obtained in the above step 2 at 105° C., impregnating it with _a ZnCl solution with a mass concentration of 40% for 10 hours, and then drying it overnight at 90° C.;

Step 4, the product obtained in the above step 3 is calcined at 900° C. for 90 min in a tube furnace _N atmosphere to obtain powdery charcoal black sludge-peanut shell activated carbon;

Step 5. Place the powdered adsorbent obtained in the above step 4 and absorbent cotton (mass ratio: activated carbon adsorbent: absorbent cotton = 1:20) in deionized water, and mechanically stir for 48 hours and then dry overnight at 105°C to obtain fixed dirt. Mud - Activated charcoal from peanut shells.

Comparative example:

A kind of preparation method of sludge-peanut shell activated carbon material comprises the steps:

Step 1. Dry and crush the remaining sludge from the urban sewage treatment plant to obtain crushed sludge; wash the peanut shells to remove impurities, dry and pulverize them to obtain crushed peanut shells; and obtain crushed sludge Mix with crushed peanut shell material in a mass ratio of 7:3 to obtain a granular mixture;

Step 2. Mix the particle mixture obtained in the above step 1 with ultrapure water and transfer it to the reactor for hydrothermal reaction. After the reactor is cooled, wash the obtained lower precipitate with 1moL/L HCl, and then use deionized Wash with water several times until the sediment is neutral;

Step 3, drying the neutral product obtained in the above step 2 at 105° C., impregnating it with _a ZnCl solution with a mass concentration of 40% for 10 hours, and then drying it overnight at 90° C.;

Step 4, the product obtained in the above step 3 is calcined at 900° C. for 90 min in a tube furnace _N atmosphere to obtain powdery charcoal black sludge-peanut shell activated carbon;

In order to evaluate the performance of the fixed sludge-peanut shell activated carbon prepared by the embodiments of the present invention, the following experiments were carried out:

Experiment 1: The fixed sludge-peanut shell activated carbon prepared in the embodiment of the present invention and the powdery sludge-peanut shell activated carbon prepared in the comparative example were carried out antibiotic removal experiment, and the experimental method was as follows:

Get 2 parts of 100mL initial concentration and be that the amoxicillin solution of 50mg/L is placed in the beaker, add respectively 420mg (wherein adsorbent quality is 20mg) the fixed sludge-peanut shell activated carbon prepared by the above-mentioned embodiment and 20mg prepared by the above-mentioned comparative example The obtained powdery sludge-peanut shell activated carbon was subjected to an adsorption experiment under the action of mechanical stirring, and was sampled after 120 minutes of adsorption to determine the removal rate of amoxicillin.

Fig. 1 is the removal rate curve of amoxicillin, the adsorbent prepared by embodiment and comparative example can reach the complete removal of amoxicillin, the fixed sludge-peanut shell activated carbon prepared by embodiment is before the reaction is carried out The reason for the slower rate of 20 minutes is that compared with the powdered activated carbon prepared in the comparative example, the effective adsorption components of the fixed sludge-peanut shell activated carbon prepared in the examples are wrapped by cotton fibers, and participate in the reaction process in the form of block solids. reaction, while the powdered activated carbon prepared in the comparative example was completely dispersed in the solution, and the effective adsorption sites were completely exposed, so the rate was faster in the early stage of the reaction. However, when the reaction lasted for 40 minutes, both of them achieved almost complete removal of amoxicillin. The most important thing is that after the end of the reaction, the powdery material of the experimental group that used the comparative example for the adsorption test was completely dispersed and was difficult to separate in the solution, while the bulk material for the experimental group that was used for the adsorption test in the example was not deformed and leaked, and the reaction It can be separated and recovered efficiently.

Experiment 2: SEM analysis was carried out to the fixed sludge-peanut shell activated carbon prepared by the embodiment of the present invention and the powdered sludge-peanut shell activated carbon prepared by the comparative example, the results are as follows:

Fig. 2 is the SEM image of the material prepared by the embodiment of the present invention and comparative example, and Fig. 2 (a) can clearly observe that loose and porous sludge-peanut shell activated carbon is attached on the cotton fiber. And under the same ratio, it is observed that the particle size of the fixed sludge-peanut shell activated carbon (Fig. 2a) prepared by the embodiment is significantly smaller than the sludge-peanut shell activated carbon (Fig. 2b) prepared by the comparative example, and its reason is that the dispersed powdery The adsorbent is prone to agglomeration, but the present invention fixes the sludge-peanut shell activated carbon adsorbent in the absorbent cotton, realizes the efficient separation and recovery of the adsorbent after use, and prevents the agglomeration of the adsorbent at the same time, which is conducive to the full use of activated carbon by antibiotics effective active sites of the adsorbent.

Experiment 3: The recovery and recycling experiment of the immobilized sludge-peanut shell activated carbon prepared in the example.

The reusability performance of adsorbents is a key factor in their commercial applications. Therefore, the fixed sludge-peanut shell activated carbon prepared by the used embodiment is reclaimed and reused. The recovered adsorbent is reused in the next cycle under the same conditions. As shown in Figure 3, the fixed sludge-peanut shell activated carbon adsorbent prepared in the embodiment can still achieve more than 85% removal rate of amoxicillin after five consecutive repeated operations, indicating that the fixed sludge-peanut shell activated carbon adsorbent prepared in the embodiment The sludge-peanut shell activated carbon adsorbent has excellent reusability, and there is no deformation and leakage of the adsorbent during repeated mechanical stirring, and it has the potential to be put into industrial application.

Claims (7)

1. A preparation method of a reusable sludge-peanut shell activated carbon material is characterized by comprising the following steps:

drying and crushing excess sludge taken from a municipal sewage treatment plant to obtain a sludge crushed material; washing the peanut shells to remove impurities, drying and crushing to obtain a crushed peanut shell material; mixing the sludge crushed material and the peanut shell crushed material to obtain a particle mixture;

step two, mixing the particle mixture obtained in the step one with ultrapure water, transferring the mixture into a reaction kettle for hydrothermal reaction, after the reaction kettle is cooled, cleaning the obtained lower-layer precipitate with 1moL/L HCl, and then cleaning the precipitate for multiple times with deionized water until the precipitate is neutral;

step three, the intermediate product obtained in the step twoDrying the sexual product, and then using ZnCl with the mass concentration of 40 percent ₂ Soaking in the solution for 10h, and drying at 90-110 deg.C overnight;

step four, putting the product obtained in the step three in a tube furnace N ₂ Calcining in the atmosphere to obtain powdery carbon black sludge-peanut shell activated carbon;

and step five, putting the powdery product obtained in the step four and absorbent cotton into deionized water, mechanically stirring for 48 hours, and drying at 90-110 ℃ overnight to obtain the fixed sludge-peanut shell activated carbon.

2. The method for preparing the reusable sludge-peanut shell activated carbon material as claimed in claim 1, wherein the method comprises the following steps: the mass ratio of the sludge crushed material to the peanut shell crushed material in the mixed particulate matter in the first step is 9-5:1-5.

3. The method for preparing a reusable sludge-peanut shell activated carbon material as claimed in claim 1 or 2, wherein: in the fourth step, the calcining temperature is 800-1000 ℃, and the calcining time is 90min.

4. The method for preparing a reusable sludge-peanut shell activated carbon material as claimed in claim 1 or 2, wherein: in the fifth step, the mass ratio of the powder adsorbent to the absorbent cotton is 1:10-40.

5. The method for preparing the reusable sludge-peanut shell activated carbon material as claimed in claim 3, wherein the method comprises the following steps: in the fifth step, the mass ratio of the powder adsorbent to the absorbent cotton is 1:10-40.

6. The use of the sludge-peanut shell activated carbon material obtained by the method for preparing the reusable sludge-peanut shell activated carbon material according to any one of claims 1 to 6 in the treatment of antibiotic wastewater.

7. The use of claim 6, wherein the immobilized sludge-peanut shell adsorbent is added into simulated wastewater containing antibiotics, and the reaction is carried out under normal temperature and pressure conditions, so that the removal of the antibiotics can be completed in a short time.

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