CN108033448A - A kind of coconut husk-sludge composite activated carbon and its preparation method and application - Google Patents

Abstract

The invention provides a method for preparing coconut shell-sludge composite activated carbon, which belongs to the field of wastewater treatment. The present invention adopts a "two-step" chemical activation method to convert excess sludge from urban sewage treatment into coconut shell-sludge composite activated carbon with economic value, recycles excess sludge from urban sewage treatment plants, and realizes sludge stabilization, reduction, harmlessness and recycling; the method has simple process, low cost, and the prepared coconut shell-sludge composite activated carbon product has well-developed pores and excellent adsorption properties; the present invention mixes coconut shell Prepare coconut shell-sludge composite activated carbon in sludge, increase the carbon content of raw materials, improve the low carbon content of sludge raw materials, and the defects of high ash content; the specific surface area of coconut shell-sludge composite activated carbon prepared by this method Larger, high adsorption value, the obtained product is used to adsorb hexavalent chromium and dyes in water, and both have good results, and the product is suitable for promotion in the field of water treatment.

Description

A kind of coconut shell-sludge composite activated carbon and its preparation method and application

technical field

The invention relates to the technical field of wastewater treatment, in particular to a coconut shell-sludge composite activated carbon and a preparation method and application thereof.

Background technique

Surplus sludge is the main waste produced by urban sewage treatment plants. Sludge has a high water content, is easy to corrupt and produces stench, and contains organic matter, heavy metals, salts and various pathogenic microorganisms. With the development of related technologies of "paying equal attention to cement", the recycling, harmless and reduction disposal of sludge has become an environmental issue that the society pays more and more attention to. Many studies have confirmed that the use of sludge activated carbon to make adsorbents has great application prospects, so it has attracted widespread attention.

At present, the research on the application of sludge activated carbon focuses on the treatment of dyes and metal ions in aqueous solution. However, the application of sludge activated carbon is closely related to the performance of the product, which depends on the properties and preparation conditions of the sludge. The traditional sludge activated carbon preparation often adopts the "one-step" chemical activation method to prepare sludge activated carbon, such as Su Xin et al. A method of preparing sludge activated carbon by using zinc chloride as an activator and adopting "one-step" carbonization activation (see "Preparation of Sludge Activated Carbon and Research on Toluene Adsorption Performance", Su Xin et al., Environmental Science and Technology, 2012, 35 (9): 25～28), the specific surface area is 539.4m ² ·g ^-1 ; Bao Hanfeng prepared sludge-based activated carbon with municipal sludge as raw material and zinc chloride as activator (see "Sludge-based activated carbon Research on the Adsorption Efficiency and Mechanism of Four Heavy Metals in Water by Activated Carbon, Bao Hanfeng, Beijing Forestry University, 2013), the specific surface area is 352.47m ² ·g ^-1 . The sludge activated carbon prepared in the prior art has the problems of small specific surface area and low proportion of micropores.

Contents of the invention

In view of this, the purpose of the present invention is to provide a preparation method of coconut shell-sludge composite activated carbon, the prepared coconut shell-sludge composite activated carbon has large specific surface area, high micropore ratio and excellent adsorption performance.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A preparation method of coconut shell-sludge composite activated carbon, comprising the following steps:

(1) drying and crushing the remaining sludge from urban sewage treatment in sequence to obtain sludge particles;

(2) the sludge granules obtained in the step (1) are mixed with coconut shell granules to obtain a granule mixture;

(3) carbonizing the particle mixture obtained in the step (2) to obtain a carbonized product;

(4) drying the charred product obtained in the step (3) with potassium hydroxide and water to obtain an intermediate product;

(5) carbonizing and activating the intermediate product obtained in the step (4) to obtain activated carbide;

(6) The activated carbon obtained in the step (5) is washed successively with hydrochloric acid and water to obtain coconut shell-sludge composite activated carbon.

Preferably, the moisture content of the sludge particles in the step (1) is lower than 10%.

Preferably, the mass ratio of sludge particles to coconut shell particles in the step (2) is 1:1-3.

Preferably, the particle diameters of the sludge particles and the coconut shell particles independently are not more than 0.3mm.

Preferably, the carbonization temperature in the step (3) is 400-600° C., and the carbonization time is 45-60 minutes.

Preferably, the drying temperature in the step (4) is 85-105° C., and the drying time is 10-12 hours.

Preferably, the carbonization activation temperature in the step (5) is 700-900° C., and the carbonization activation time is 45-60 minutes.

The present invention also provides the coconut shell-sludge composite activated carbon prepared by the preparation method described in the above technical scheme, the specific surface area of the coconut shell-sludge composite activated carbon is 457.47～583.8m ² ·g ^-1 , and the total pore volume is 0.1865-0.2380 cm ² ·g ^-1 , the micropore volume is 0.1198-0.1529 ^{cm 2} ·g ^-1 , the micropore ratio is 13.98-17.84%, and the average pore diameter is 2.19-2.79 nm.

The present invention also provides the application of the coconut shell-sludge composite activated carbon described in the technical solution in the adsorption of heavy metal ions and dyes.

The invention provides a preparation method of coconut shell-sludge composite activated carbon. The remaining sludge from urban sewage treatment is sequentially dried and pulverized to obtain sludge particles and then mixed with coconut shell particles to obtain a particle mixture and a particle mixture. Carry out carbonization to obtain a carbonized product, activate the carbonized product, potassium hydroxide and water, dry and carbonize and activate to obtain activated carbonized products, and then wash the activated carbonized products with hydrochloric acid and water in sequence to obtain coconut shell-sludge composite activated carbon. The present invention adopts a "two-step" chemical activation method to prepare coconut shell-sludge composite activated carbon by doping coconut shells into sludge, increasing the carbon content of raw materials, and improving the low carbon content and high ash content of sludge raw materials. defects; the coconut shell-sludge composite activated carbon prepared by this method has a large specific surface area and high adsorption value, and the obtained product is used to adsorb hexavalent chromium and dyes in water bodies, and has good results, and the product is suitable for promotion in the field of water treatment ; The present invention converts the excess sludge of urban sewage treatment plants into coconut shell-sludge composite activated carbon with economic value, recycles the excess sludge of urban sewage treatment plants, and realizes the stabilization, reduction and harmlessness of sludge The method has the characteristics of simple process, low cost, well-developed pores of the prepared coconut shell-sludge composite activated carbon product, and excellent adsorption performance.

The data of the embodiment shows that the specific surface area of the coconut shell-sludge composite activated carbon prepared by the present invention is 457.47～583.8m ² ·g ^-1 , the total pore volume is 0.1865～0.2380cm ² ·g ^-1 , and the micropore volume is 0.1198～0.1529cm ² ·g ^-1 , the proportion of micropores is 13.98～17.84%, and the average pore diameter is 2.19～2.79nm. It is applied to the removal of hexavalent chromium and rhodamine B in water, and the effect is good. The removal of hexavalent chromium The rate is 99.97%, the removal rate of rhodamine B is 99.56%, and the iodine value is as high as 663.97 mg·g ^-1 .

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is the SEM image of the coconut shell-sludge composite activated carbon that the conventional sludge activated carbon that comparative example of the present invention makes and embodiment 1 make;

Fig. 2 is the BET image of the coconut shell-sludge composite activated carbon that the conventional sludge activated carbon that the comparative example of the present invention makes and embodiment 1 make.

Detailed ways

The invention provides a kind of preparation method of coconut shell-sludge composite activated carbon, comprises the following steps:

(1) drying and crushing the remaining sludge from urban sewage treatment in sequence to obtain sludge particles;

(2) the sludge granules obtained in the step (1) are mixed with coconut shell granules to obtain a granule mixture;

(3) carbonizing the particle mixture obtained in the step (2) to obtain a carbonized product;

(4) drying the carbonized product, potassium hydroxide and water obtained in the step (3) to obtain an intermediate product;

(5) carbonizing and activating the intermediate product obtained in the step (4) to obtain activated carbide;

(6) The activated carbon obtained in the step (5) is washed successively with hydrochloric acid and water to obtain coconut shell-sludge composite activated carbon.

The invention sequentially dries and pulverizes the excess sludge derived from urban sewage treatment to obtain sludge particles. The invention dries the excess sludge from urban sewage treatment to obtain dry sludge. In the present invention, the moisture content of the sludge particles is preferably lower than 10%. The present invention has no special limitation on the drying method, and the drying method known to those skilled in the art can be adopted. Specifically, such as drying in a drying box, the present invention has no special limitation on the drying temperature and time. It only needs to be able to reduce the moisture content of the sludge particles to less than 10%.

The present invention has no special limitation on the types and contents of components in the excess sludge from urban sewage treatment, such as excess sludge from urban sewage treatment plants.

After obtaining the dried sludge, the present invention pulverizes the dried sludge to obtain sludge granules. In the present invention, the particle size of the sludge particles is preferably not more than 0.3mm. The present invention has no special limitation on the specific manner of crushing, as long as the dried sludge can be crushed to a required particle size.

After the sludge granules are obtained, the present invention mixes the obtained sludge granules with coconut shell granules to obtain a granule mixture. In the present invention, the particle size of the coconut shell particles is preferably not more than 0.3mm. The present invention does not have special limitation to the source of coconut shell, adopts commercially available commodity well-known by those skilled in the art. In the present invention, coconut shells are preferably crushed to obtain coconut shell particles. The present invention has no special limitation on the pulverization method, as long as the coconut shell particles required by the particle size can be obtained. In the present invention, the water content of the coconut shell particles is preferably 5-8%, more preferably 6%. The invention mixes coconut shells into sludge to prepare coconut shell-sludge composite activated carbon, increases the carbon content of raw materials, and improves the defects of low carbon content and high ash content of sludge raw materials. The present invention has no special limitation on the mixing method, and a mixing method well known to those skilled in the art can be used, specifically, such as stirring.

In the present invention, the mass ratio of the sludge particles to the coconut shell particles is preferably 1:1-3, more preferably 1:1-1.5.

After the particle mixture is obtained, the present invention carbonizes the particle mixture to obtain a carbonized product. In the present invention, the carbonization temperature is preferably 400-600°C, more preferably 500-550°C, and the carbonization time is preferably 45-60 minutes, more preferably 50-55 minutes. In the present invention, the heating rate to the carbonization temperature is preferably 35-50°C/min, more preferably 40-45°C/min. In the present invention, the carbonization is preferably carried out in a box-type resistance furnace. In the present invention, the carbonization causes macromolecular organic matter to decompose under certain temperature conditions to form charcoal or solid residues. The volatile substances in the raw materials are removed or transformed, and a porous carbon network is obtained through a series of chemical reactions. structure.

After obtaining the carbonized product. In the present invention, the carbonized product, potassium hydroxide and water are activated and then dried to obtain an intermediate product.

In the present invention, the order of adding the carbonized product, potassium hydroxide and water is preferably to first mix potassium hydroxide and water to obtain a potassium hydroxide solution, and then dip the carbonized product into the potassium hydroxide solution. In the present invention, the concentration of the potassium hydroxide solution is preferably 2-3 mol/L, more preferably 2.5 mol/L. In the present invention, the mass ratio of the carbonization product to the potassium hydroxide solution is preferably 1:1-2, more preferably 1:1.5.

In the present invention, the activation time is preferably longer than 20 hours, more preferably 24 hours. In the present invention, the activation enables the activator potassium hydroxide to fully react with the oxygen-containing functional groups on the surface of the carbonized product, which is beneficial to the development of pores. In the present invention, the activation temperature is preferably room temperature without additional heating or cooling.

After the activation is completed, the present invention dries the activated product to obtain an intermediate product. In the present invention, the drying temperature is preferably 85-105°C, more preferably 90-95°C; the drying time is preferably 24-36 hours, more preferably 28-32 hours. In the present invention, the purpose of the drying is to ensure that only solid particles exist in the intermediate product, so that the solid particles can be fully carbonized and activated at high temperature.

After the intermediate product is obtained, the present invention carbonizes and activates the intermediate product to obtain activated carbide. In the present invention, the carbonization activation temperature is preferably 700-900°C, more preferably 800-850°C, and the carbonization activation time is preferably 45-60 minutes, more preferably 50-55 minutes. In the present invention, the heating rate to the carbonization activation temperature is preferably 35-50°C/min, more preferably 40-45°C/min. In the present invention, the carbonization activation is preferably performed in a box-type resistance furnace. In the present invention, during the carbonization activation process, the activator interacts with the carbonized product under certain conditions, expands the initial pores of the carbonized product and develops new channels, so as to produce a rich pore structure and form surface active groups , to obtain activated carbon.

After the activated carbon is obtained, the present invention washes the activated carbon with hydrochloric acid and water in sequence to obtain the coconut shell-sludge composite activated carbon. In the present invention, the concentration of the hydrochloric acid is preferably 2-4 mol/L, more preferably 3 mol/L. In the present invention, the number of washings with hydrochloric acid is preferably 3 times, and the mass ratio of activated carbon to hydrochloric acid is not particularly limited during each hydrochloric acid washing. In the present invention, the hydrochloric acid washing can adjust the pH value, and at the same time wash away the ash produced by carbonization activation.

After the hydrochloric acid washing is completed, the present invention washes the hydrochloric acid washing product with water. In the present invention, there is no special limitation on the number of water-based washings and the amount of water used for each washing, as long as the hydrochloric acid washing product can be washed until the pH value is 7-8.

After the water washing is completed, in the present invention, the washed product is preferably dried and ground in sequence to obtain the coconut shell-sludge composite activated carbon. In the present invention, the drying can remove moisture. In the present invention, the particle size of the ground product is preferably 0.150 mm. In the present invention, there is no special limitation on the specific methods of drying and grinding, and operations known to those skilled in the art can be used.

The present invention also provides the coconut shell-sludge composite activated carbon prepared by the preparation method described in the above technical scheme, the specific surface area of the coconut shell-sludge composite activated carbon is 457.47～583.8m ² ·g ^-1 , and the total pore volume is 0.1865-0.2380 cm ² ·g ^-1 , the micropore volume is 0.1198-0.1529 ^{cm 2} ·g ^-1 , the micropore ratio is 13.98-17.84%, and the average pore diameter is 2.19-2.79 nm.

In the present invention, the coconut shell-sludge composite activated carbon preferably includes the following elements in weight percentage: Si45～60%, Al 6～12%, Fe 18～22%, Cl 3～7%, K 4～ 8%, Ca 3-7%, Mg 3-7%, and the balance C.

The present invention also provides the application of the coconut shell-sludge composite activated carbon described in the technical solution in the adsorption of heavy metal ions and dyes, more preferably the adsorption of heavy metal ions and dyes in wastewater. The present invention has no special limitation on the source of the waste water.

In the present invention, when the heavy metal ion is hexavalent chromium and the dye is rhodamine B, the concentration of hexavalent chromium in the waste water is preferably 50 mol/L, and the concentration of rhodamine B in the waste water is preferably 20 mol/L.

In the present invention, the volume ratio of the mass of the coconut shell-sludge composite activated carbon to the waste water is preferably 0.3-0.5 g/mL.

In the present invention, the adsorption is preferably carried out on a water bath oscillator, the vibration frequency of the water bath oscillator is preferably 190 times/min, and the vibration amplitude is preferably 40 mm. In the present invention, the adsorption is preferably carried out at room temperature without additional heating or cooling, and the adsorption time is preferably 6-12 hours.

In the present invention, the pH value of the wastewater during the adsorption is preferably 4.

The coconut shell-sludge composite activated carbon provided by the present invention and its preparation method and application are described in detail below in conjunction with the examples, but they cannot be interpreted as limiting the protection scope of the present invention.

comparative example

(1) Send the remaining sludge from urban sewage treatment plants with a water content of more than 85% into an oven to dry until the water content is lower than 10% to obtain dry sludge; crush and sieve the dry sludge with 50 meshes to obtain a particle size of no more than 0.3mm sludge particles, weigh 20g of dry sludge.

(2) Send the above sludge particles into a box-type resistance furnace, carbonize and activate at a temperature of 500° C. for 45 minutes, and control the heating rate at 35° C./min to obtain carbonized products.

(3) Add the carbonized product obtained in step 2 into the potassium hydroxide solution and stir evenly. The concentration of potassium hydroxide is 2.5mol/L, and the impregnation ratio is 1:1.5 (mass ratio). Dry for 24 hours.

(4) Put the intermediate product obtained in step 3 into a box-type resistance furnace, raise the temperature to 800° C. at a heating rate of 35° C./min, and keep the temperature constant for 60 minutes.

(5) After the activated carbide obtained in step 4 is cooled to room temperature, it is washed 3 times with 3 mol/L hydrochloric acid, then washed with deionized water until the pH value is 7.5, and the product is dried and ground to obtain conventional sludge activated carbon .

Example 1

Send the remaining sludge from urban sewage treatment plants with a moisture content of more than 85% into an oven to dry until the moisture content is lower than 10% to obtain dry sludge; grind the dry sludge and coconut shells separately, and sieve through 50 meshes to obtain a particle size not exceeding For 0.3mm sludge particles and coconut shell particles, weigh 10g of dry sludge and 10g of coconut shell particles according to the mass ratio of 1:1, and mix them evenly. The rest of the preparation methods are the same as in Example 1 to prepare coconut shell-sludge activated carbon.

Fig. 1 is the SEM image of the coconut shell-sludge composite activated carbon that the conventional sludge activated carbon that comparative example of the present invention makes and embodiment 1 make; Fig. 2 is the conventional sludge activated carbon that comparative example of the present invention makes and embodiment 1 The BET image (test condition: analysis temperature 77.350K, 6 hours of adsorption and desorption time) of the coconut shell-sludge composite active carbon that makes, as can be seen from Fig. 1～2, the coconut shell that the present invention makes-sludge composite Activated carbon has a large specific surface area and a high proportion of micropores.

Example 2

(1) Send the remaining sludge of urban sewage treatment plants with a water content of more than 85% into an oven to dry until the water content is lower than 10% to obtain dry sludge; crush the dry sludge and coconut shells separately, and sieve through 50 meshes to obtain granules For sludge particles and coconut shell particles with a diameter not exceeding 0.3mm, weigh 10g of dry sludge and 10g of coconut shell particles according to the mass ratio of 1:1, and mix them evenly.

(2) Send the above sludge particles into a box-type resistance furnace, carbonize and activate at a temperature of 500° C. for 45 minutes, and control the heating rate at 35° C./min to obtain carbonized products.

(3) Add the charred product obtained in step 2 into the potassium hydroxide solution and stir evenly, the concentration of potassium hydroxide is 2mol/L, and the impregnation ratio is 1:1.5 (mass ratio, W solid: W potassium hydroxide=1: 1.5, the same below), immerse at room temperature for 24 hours and then dry at 105°C for 24 hours.

(4) Put the intermediate product obtained in step 3 into a box-type resistance furnace, raise the temperature to 800° C. at a heating rate of 35° C./min, and keep the temperature constant for 60 minutes.

(5) After the active carbide obtained in step 4 is cooled to room temperature, it is washed 3 times with 3mol/L hydrochloric acid with a concentration, and then washed with deionized water until the pH value is 7.5, and the product is dried and ground to obtain coconut shell-pollution Mud composite activated carbon.

Example 3

(1) Send the remaining sludge of urban sewage treatment plants with a water content of more than 85% into an oven to dry until the water content is lower than 10% to obtain dry sludge; crush the dry sludge and coconut shells separately, and sieve through 50 meshes to obtain granules For sludge particles and coconut shell particles with a diameter not exceeding 0.3mm, weigh 10g of dry sludge and 10g of coconut shell particles according to the mass ratio of 1:1, and mix them evenly.

(2) Send the above sludge particles into a box-type resistance furnace, carbonize and activate at a temperature of 500° C. for 45 minutes, and control the heating rate at 35° C./min to obtain carbonized products.

(3) Add the carbonized product obtained in step 2 into the potassium hydroxide solution and stir evenly. The concentration of potassium hydroxide is 3mol/L, and the impregnation ratio is 1:1.5 (mass ratio). After immersing at room temperature for 24 hours, bake at 105°C Dry for 24 hours.

(4) Put the intermediate product obtained in step 3 into a box-type resistance furnace, raise the temperature to 800° C. at a heating rate of 35° C./min, and keep the temperature constant for 60 minutes.

(5) After the active carbide obtained in step 4 is cooled to room temperature, it is washed 3 times with 3mol/L hydrochloric acid with a concentration, and then washed with deionized water until the pH value is 7.5, and the product is dried and ground to obtain coconut shell-pollution Mud composite activated carbon.

Example 4

(1) Send the remaining sludge of urban sewage treatment plants with a water content of more than 85% into an oven to dry until the water content is lower than 10% to obtain dry sludge; crush the dry sludge and coconut shells separately, and sieve through 50 meshes to obtain granules For sludge particles and coconut shell particles with a diameter not exceeding 0.3mm, weigh 10g of dry sludge and 10g of coconut shell particles according to the mass ratio of 1:1, and mix them evenly.

(2) Send the above sludge particles into a box-type resistance furnace, carbonize and activate at a temperature of 500° C. for 45 minutes, and control the heating rate at 35° C./min to obtain carbonized products.

(3) Add the carbonized product obtained in step 2 into the potassium hydroxide solution and stir evenly. The concentration of potassium hydroxide is 2.5mol/L, the impregnation ratio is 1:1.5, impregnate at room temperature for 24h, and then dry at 105°C for 24h.

(4) Put the intermediate product obtained in step 3 into a box-type resistance furnace, raise the temperature to 700° C. at a heating rate of 35° C./min, and keep the temperature constant for 60 minutes.

(5) After the active carbide obtained in step 4 is cooled to room temperature, it is washed 3 times with 3mol/L hydrochloric acid with a concentration, and then washed with deionized water until the pH value is 7.5, and the product is dried and ground to obtain coconut shell-pollution Mud composite activated carbon.

Example 5

(1) Send the remaining sludge of urban sewage treatment plants with a water content of more than 85% into an oven to dry until the water content is lower than 10% to obtain dry sludge; crush the dry sludge and coconut shells separately, and sieve through 50 meshes to obtain granules For sludge particles and coconut shell particles with a diameter not exceeding 0.3mm, weigh 10g of dry sludge and 10g of coconut shell particles according to the mass ratio of 1:1, and mix them evenly.

(2) Send the above sludge particles into a box-type resistance furnace, carbonize and activate at a temperature of 500° C. for 45 minutes, and control the heating rate at 35° C./min to obtain carbonized products.

(3) Add the carbonized product obtained in step 2 into the potassium hydroxide solution and stir evenly. The concentration of potassium hydroxide is 2.5mol/L, the impregnation ratio is 1:1.5, impregnate at room temperature for 24h, and then dry at 105°C for 24h.

(4) Put the intermediate product obtained in step 3 into a box-type resistance furnace, raise the temperature to 900° C. at a heating rate of 35° C./min, and keep the temperature constant for 60 minutes.

(5) After the active carbide obtained in step 4 is cooled to room temperature, it is washed 3 times with 3mol/L hydrochloric acid with a concentration, and then washed with deionized water until the pH value is 7.5, and the product is dried and ground to obtain coconut shell-pollution Mud composite activated carbon.

Analysis data is as shown in table 1, as can be seen from table 1, the coconut shell-sludge composite activated carbon that the present invention makes has large specific surface area, and the micropore ratio is high. Table 2 is the iodine value adsorption data of conventional sludge activated carbon and the obtained coconut shell-sludge composite activated carbon of embodiment 1～5 that comparative example makes, as can be seen from table 2, the coconut shell-sludge composite that the present invention makes Activated carbon has a high iodine value.

Table 1 Analysis data of pore structure of conventional sludge activated carbon and coconut shell-sludge composite activated carbon

The conventional sludge activated carbon that table 2 comparative example makes and embodiment 1～5 gained coconut shell-sludge composite activated carbon iodine value adsorption data

Example 6

(1) Prepare 100mL of waste water containing 50mol/L hexavalent chromium and place it in a 250mL conical flask with a stopper, and adjust the pH value of the solution to 4;

(2) Take by weighing 0.3g coconut shell-sludge composite activated carbon and add to the solution containing hexavalent chromium;

(3) Place the Erlenmeyer flask on a water bath oscillator, adjust the vibration frequency to 190 times/min, the amplitude to 40mm, and shake at room temperature 25°C for 6h;

(4) Remove the Erlenmeyer flask and filter the liquid, refer to "Determination of Hexavalent Chromium in Water Quality-Diphenylcarbazide Spectrophotometry", calculate the residual amount of Hexavalent Chromium, and the removal rate is 99.97%.

Example 7

(1) Prepare 100 mL of rhodamine B solution containing 20 mg/L and place it in a 250 mL conical flask with a stopper, and adjust the pH value of the solution to 4;

(2) Take by weighing 0.5g coconut shell-sludge composite activated carbon and add in the solution;

(3) Place the Erlenmeyer flask on a water bath oscillator, adjust the vibration frequency to 190 times/min, the amplitude to 40 mm, and shake at room temperature 25°C for 12 hours;

(4) Remove the Erlenmeyer flask and filter the liquid. With reference to GB 7467-87, calculate the residual amount of Rhodamine B to be 0.0088 mg, and the removal rate is 99.56%.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (9)

1. a kind of preparation method of coconut husk-sludge composite activated carbon, comprises the following steps：

(1) it will be dried and crush successively from the excess sludge of municipal sewage treatment, obtain mud granule；

(2) mud granule that the step (1) obtains is mixed with coconut husk particle, obtains granulate mixture；

(3) granulate mixture that the step (2) obtains is carbonized, obtains carbonizing production；

(4) dried after the carbonizing production that the step (3) obtains is activated with potassium hydroxide with water, obtain intermediate product；

(5) intermediate product for obtaining the step (4) carries out carbonization-activation, obtains activated carbide；

(6) activated carbide for obtaining the step (5) uses hydrochloric acid and water washing successively, obtains coconut husk-sludge composite reactive Charcoal.

2. preparation method according to claim 1, it is characterised in that the moisture content of mud granule is low in the step (1) In 10%.

3. preparation method according to claim 1 or 2, it is characterised in that mud granule and coconut husk in the step (2) The mass ratio of grain is 1:1~3.

4. preparation method according to claim 3, it is characterised in that the particle diameter of the mud granule and coconut husk particle is independent Ground is no more than 0.3mm.

5. preparation method according to claim 1, it is characterised in that in the step (3) temperature of charing for 400~ 600 DEG C, the time of the charing is 45~60min.

6. preparation method according to claim 1, it is characterised in that the temperature of drying is 85~105 in the step (4) DEG C, the time of the drying is 10~12h.

7. preparation method according to claim 1, it is characterised in that the temperature of carbonization-activation is 700 in the step (5) ~900 DEG C, the time of the carbonization-activation is 45~60min.

8. coconut husk made from preparation method described in claim 1~7 any one-sludge composite activated carbon, it is characterised in that institute The specific surface area for stating coconut husk-sludge composite activated carbon is 457.47~583.8m²·g^-1,

Total hole volume is 0.1865~0.2380cm²·g^-1, micropore volume is 0.1198~0.1529cm²·g^-1, micropore ratio For 13.98~17.84%, average pore size is 2.19~2.79nm.

9. application of the coconut husk-sludge composite activated carbon in absorption heavy metal ion and dyestuff described in claim 8.