A carbon-based conditioning agent and its preparation method and application

Abstract

The present invention belongs to the technical field of sludge dewatering treatment, and specifically relates to a carbon-based conditioning agent and its preparation method and application. The carbon-based conditioning agent has an average particle size of 15-45nm and a specific surface area of ​​600-1000m 2 / g, a porosity of 50-90%, and an average pore size of 10-60nm; based on the mass of the carbon-based conditioner, the graphite crystal content is 50-75wt%; the specific average particle size, specific surface area, and porosity of the carbon-based conditioner give the carbon-based conditioner excellent adsorption properties. When applied to sludge electric dewatering technology, the carbon-based conditioner can adsorb EPS, alleviate filter cloth clogging, and improve the electric dewatering effect; the specific graphite crystal content of the carbon-based conditioner provides a large number of free electrons, which form conductive channels inside the carbon-based conditioner. When an electric field is applied, the free electrons synergistically interact with the anions and cations ionized from the sludge to improve the conductivity of the entire system.

Description

Technical Field

[0001] The invention belongs to the technical field of sludge dewatering treatment, and particularly relates to a carbon-based conditioning agent and a preparation method and application thereof. Background Art

[0002] As the end product of sewage biological treatment, sludge poses huge challenges to its treatment due to its high water holding capacity (initial moisture content is generally higher than 95%) and complex chemical composition (such as extracellular polymers (EPS), colloidal substances, heavy metals and pathogens).

[0003] The primary task of sludge treatment is to reduce sludge volume through solid-liquid separation to lower transportation and handling costs. Furthermore, while sludge has a high water content and low energy density, it is rich in organic matter and contains biomass carbon sources such as proteins, polysaccharides, and lipids. These properties make sludge a highly promising renewable energy resource. Therefore, how to effectively dehydrate sludge while simultaneously increasing its resource value has become a key issue that needs to be addressed in the current sludge treatment field.

[0004] Sludge electrical dewatering technology (e.g., electroosmosis sludge dewatering) is an emerging sludge dewatering method. Electrolytes in the sludge dissociate into cations and anions, which migrate in a targeted manner under the action of an electric field. These cations and anions aggregate and compress the sludge structure, extracting the internal water and achieving efficient sludge dewatering. However, insufficient electrolyte content and excessive water content in the sludge dilute the water, reducing the electrolyte concentration and electrical conductivity. Furthermore, during the sludge dewatering process, extracellular polymeric substances (EPS) in the sludge dissolve and release, migrating along with the water to the surface or internal pores of the filter medium, clogging the filter channels, increasing filtration resistance, and deteriorating the sludge dewatering effect. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of poor electrical conductivity of the system in the existing sludge electric dehydration process, and as the dehydration proceeds, the filter medium will become clogged, thereby reducing the dehydration effect, so that the moisture content of the sludge after final dehydration is still high, thereby providing a carbon-based conditioner and its preparation method and application.

[0006] To this end, the present invention provides the following technical solutions:

[0007] The first aspect of the present invention provides a carbon-based conditioning agent, wherein the average particle size of the carbon-based conditioning agent is 15-45 μm, the specific surface area is 600-1000 m 2 / g, porosity of 50-90%, and average pore size of 10-60nm;

[0008] The graphite crystal content is 50-75 wt % based on the mass of the carbon-based conditioning agent.

[0009] According to the present invention, the carbon-based conditioning agent has an average particle size of 15-20 μm and a specific surface area of ​​800-1000 m 2 / g, porosity of 60-80%, and average pore size of 10-30nm;

[0010] The graphite crystal content is 50-70 wt % based on the mass of the carbon-based conditioning agent.

[0011] The second aspect of the present invention provides a method for preparing a carbon-based conditioning agent, wherein the preparation method comprises the following steps: mixing biomass activated carbon and solid alkali, pyrolyzing the mixture in a gas atmosphere containing a crackable carbon source gas, and acid washing to obtain a carbon-based conditioning agent; wherein the pyrolysis conditions include: heating to 800-1500°C at a rate of 5-20°C / min for 1-2h.

[0012] In the present invention, the biomass activated carbon is dried before being mixed with the alkali. The drying is conventional in the art, the drying temperature is 80-100°C, and the drying time is adjusted according to the size of the material, as long as the drying is complete. The dried biomass activated carbon does not contain moisture, which can prevent water from evaporating into water vapor in a high-temperature environment, resulting in changes in the gas atmosphere, and further affecting the properties of the obtained carbon-based conditioner. In addition, water vapor combines with alkali to form a corrosive solution, which will affect the service life of the tubular furnace.

[0013] In the present invention, the mixing is conventional mixing in the art, and the mixing is uniform.

[0014] In the present invention, the solid base is a conventional base in the art. Typically, but not limited to, the solid base includes at least one of solid potassium hydroxide and solid sodium hydroxide.

[0015] In the present invention, biomass activated carbon and solid alkali are placed in a porcelain boat, pyrolyzed in a tube furnace, and naturally cooled to room temperature after pyrolysis to obtain a mixture.

[0016] According to the present invention, the crackable carbon source-containing gas includes at least one of alkanes, alkenes, alkynes, and carbon monoxide.

[0017] According to the present invention, the crackable carbon source gas includes at least one of methane, ethylene, propyne and carbon monoxide.

[0018] According to the present invention, the gas atmosphere further comprises a protective gas, and the volume ratio of the gas containing the crackable carbon source to the protective gas is 1:3-10.

[0019] In the present invention, the protective gas is a conventional gas in the art, typically but not limitedly, including at least one of nitrogen and helium.

[0020] In the present invention, the flow rate of the gas for creating the gas atmosphere is 100-200 mL / min.

[0021] According to the present invention, the mass ratio of the biomass activated carbon to the solid alkali is 1:2-5.

[0022] According to the present invention, the biomass activated carbon includes at least one of coconut shell activated carbon and straw activated carbon.

[0023] According to the present invention, the mass ratio of the biomass activated carbon to the solid alkali is 1:4.5-5.

[0024] According to the present invention, the pyrolysis conditions include: a heating rate of 5-10°C / min and a temperature of 900-1000°C.

[0025] According to the present invention, the mixture is washed with water until it is neutral and then dried, and then acid washed. The acid washed product is washed with water until it is neutral and then dried to obtain a carbon-based conditioner.

[0026] In the present invention, the mixture is washed with water to a neutral state, then dried and then acid-washed. Washing to a neutral state removes residual alkaline substances on the surface, preventing the reaction of the alkali on the surface with the acid from releasing large amounts of heat and damaging the structure of the carbon-based conditioning agent. It also prevents salt impurities generated by acid-base neutralization from clogging pores. Acid washing further removes impurities, optimizes pore distribution, and improves material purity. Washing the acid-washed product with water to a neutral state and then drying it removes the acid introduced during the acid wash, preventing acid corrosion on the material and ensuring material stability during storage and processing. Laboratory water (deionized water) is used for washing, and drying is performed in a vacuum desiccator. The pickling comprises immersing the mixture in acid, wherein the volume of the acid is not limited, as long as the volume of the acid can completely cover the mixture, and the immersion time is 1-3 hours; stirring is also performed during immersion to ensure more thorough pickling; the acid comprises nitric acid and / or sulfuric acid, and when used, water is added to prepare an acid aqueous solution, and the concentration of the acid aqueous solution is 15-30 g / L; after immersion, solid-liquid separation (filtration) is performed, and the solid is collected for post-processing.

[0027] A third aspect of the present invention provides a use of the aforementioned carbon-based conditioner or the carbon-based conditioner prepared by the aforementioned preparation method in sludge electric dewatering.

[0028] The technical solution of the present invention has the following advantages:

[0029] 1. The present invention provides a carbon-based conditioning agent, wherein the average particle size of the carbon-based conditioning agent is 15-45 μm, and the specific surface area is 600-1000 m 2 / g, porosity is 50-90%, and average pore size is 10-60nm; based on the mass of the carbon-based conditioner, the graphite crystal content is 50-75wt%; the specific average particle size, specific surface area, and porosity of the carbon-based conditioner give the carbon-based conditioner excellent adsorption performance. When applied to sludge electric dewatering technology, the carbon-based conditioner can adsorb EPS, relieve filter cloth blockage, and improve the electric dewatering effect; the specific graphite crystal content of the carbon-based conditioner provides a large number of free electrons, which form conductive channels inside the carbon-based conditioner. After the electric field is applied, the free electrons synergistically act with the anions and cations ionized from the sludge to improve the conductivity of the entire system.

[0030] 2. The specific average particle size, specific surface area, porosity, and pore size of the carbon-based conditioning agent of the present invention can further accurately capture EPS and significantly improve filtration efficiency; the specific graphite crystal content can further construct a denser and more efficient conductive channel.

[0031] 3. The present invention provides a method for preparing a carbon-based conditioner, wherein the preparation method comprises the following steps: mixing biomass activated carbon and solid alkali, pyrolyzing the mixture in a gas atmosphere containing a crackable carbon source gas, and acid washing to obtain a carbon-based conditioner; wherein the pyrolysis conditions include: heating to 800-1500°C at a rate of 5-20°C / min for 1-2h; mixing the biomass activated carbon and the solid alkali, the solid alkali can corrode the carbon skeleton to form a microporous or mesoporous structure, and can also provide an alkaline environment to promote carbon atom bonding, transforming to an ordered graphite structure, and generating graphite crystals; the crackable carbon source gas is cracked under specific pyrolysis conditions and deposited on the surface and pores of the biomass activated carbon. Although the pore size is reduced to a certain extent, it can fill the structural defects of the pore wall of the biomass activated carbon, making the pore structure more perfect; acid washing can remove impurities, optimize the pore structure, and improve the purity of the material; and the preparation method of the present invention is simple, the raw materials are easily available, the cost is low, and it can be promoted on a large scale.

[0032] 4. The present invention uses a crackable carbon source gas and a protective gas together. Compared with using only the crackable gas, the protective gas can slow down the cracking rate, prevent the carbon from depositing too quickly and causing agglomeration, and further ensure the stability of the particle size and pore size of the carbon-based conditioning agent. At the same time, the use of a crackable carbon source gas alone has the risk of flammability and explosion. The introduction of the protective gas can improve the safety of the system and reduce costs.

[0033] 5. The specific mass ratio of biomass activated carbon and solid base in the present invention can further adjust the particle size and pores of the final carbon-based conditioner, thereby improving the overall adsorption performance; and can enable more carbon atoms to form graphite crystals at a specific temperature, and make the arrangement of graphite crystals more regular.

[0034] 6. The specific pyrolysis conditions in the present invention can further make the bonding and rearrangement of carbon atoms more orderly, so that the average particle size, specific surface area, porosity and average pore size of the carbon-based conditioning agent can be further regulated, thereby improving the adsorption performance; and because the orderliness of carbon atoms is increased, the lattice defects of the graphite crystals are reduced, thereby improving the conductivity.

[0035] 7. The present invention uses water to wash the mixture to neutrality and then dries it, and then performs pickling. Washing to neutrality can remove residual alkaline substances on the surface, avoid the alkali on the surface of the mixture reacting with the acid used in pickling to release a large amount of heat, destroy the structure of the carbon-based conditioner, and also avoid the salt impurities generated by acid-base neutralization to clog the pores; pickling can further remove impurities, optimize the pore distribution, and improve the purity of the material. Using water to wash the pickled product to neutrality and then drying it can remove the acid introduced in the pickling, prevent the acid from corroding the material, and ensure the stability of the material storage and processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 1 is the XRD pattern of the carbon-based conditioning agent of Example 1 and Comparative Example 1;

[0038] Figure 2 1 is the XRD pattern of the carbon-based conditioning agent of Example 4 and Comparative Example 1. DETAILED DESCRIPTION

[0039] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0040] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0041] Coconut shell activated carbon: purchased from Jiangsu Pushida Environmental Protection Technology Co., Ltd.; the name is PSD;

[0042] The purity of solid potassium hydroxide is analytical grade;

[0043] The concentration of dilute nitric acid solution is 30g / L;

[0044] The water used in the examples and comparative examples was deionized water.

[0045] Example 1

[0046] This embodiment provides a carbon-based conditioning agent, the preparation method of which includes the following steps:

[0047] Coconut shell activated carbon is dried at 100°C, and the dried coconut shell activated carbon and solid potassium hydroxide are evenly mixed in a porcelain boat at a mass ratio of 1:2. The porcelain boat is placed in a tube furnace, and a mixed gas of methane and nitrogen is introduced, wherein the volume ratio of methane to nitrogen is 1:3, and the flow rate of the mixed gas is 100 mL / min; the temperature is increased to 1000°C at a rate of 5°C / min and heated for 1.5 hours, and naturally cooled to room temperature to obtain a mixture; the mixture is washed with water to neutrality, dried in a vacuum desiccator for 12 hours, and the dried product is immersed in a dilute nitric acid solution and stirred for 1 hour. The solid is collected after separation by suction filtration, washed with water to neutrality, and dried in a vacuum desiccator for 12 hours to obtain a carbon-based conditioner.

[0048] Example 2

[0049] This embodiment provides a carbon-based conditioning agent, the preparation method of which includes the following steps:

[0050] Coconut shell activated carbon is dried at 100°C, and the dried coconut shell activated carbon and solid sodium hydroxide are uniformly mixed in a porcelain boat at a mass ratio of 1:4. The porcelain boat is placed in a tube furnace, and a mixed gas of methane and nitrogen is introduced, wherein the volume ratio of methane to nitrogen is 1:5 and the flow rate of the mixed gas is 120 mL / min; the temperature is increased to 1500°C at a rate of 10°C / min and heated for 1.5 hours, and naturally cooled to room temperature to obtain a mixture; the mixture is washed with water to neutrality, dried in a vacuum desiccator for 12 hours, and the dried product is immersed in a dilute nitric acid solution and stirred for 1 hour. The solid is collected after separation by suction, washed with water to neutrality, and dried in a vacuum desiccator for 12 hours to obtain a carbon-based conditioner.

[0051] Example 3

[0052] This embodiment provides a carbon-based conditioning agent, the preparation method of which includes the following steps:

[0053] The method of Example 1 is the same, except that the pyrolysis conditions include: heating to 1500° C. at a rate of 20° C. / min and heating for 1.5 h.

[0054] Example 4

[0055] This embodiment provides a carbon-based conditioning agent, the preparation method of which includes the following steps:

[0056] The method of Example 2 is the same, except that the mass ratio of coconut shell activated carbon to solid potassium hydroxide is 1:5.

[0057] Example 5

[0058] This embodiment provides a carbon-based conditioning agent, the preparation method of which includes the following steps:

[0059] The method of Example 2 was followed, except that methane was replaced with an equal volume of ethylene.

[0060] Example 6

[0061] This embodiment provides a carbon-based conditioning agent, the preparation method of which includes the following steps:

[0062] The method of Example 2 was followed, except that methane was replaced with an equal volume of acetylene.

[0063] Comparative Example 1

[0064] This comparative example provides a carbon-based conditioning agent, the preparation method of which comprises the following steps:

[0065] The process was carried out in the same manner as in Example 1, except that no solid potassium hydroxide was added.

[0066] Comparative Example 2

[0067] This comparative example provides a carbon-based conditioning agent, the preparation method of which comprises the following steps:

[0068] The method of Example 1 is the same as that of Example 1, except that only nitrogen is introduced, and the volume of nitrogen is equal to the total volume of methane and nitrogen in Example 3.

[0069] Comparative Example 3

[0070] This comparative example provides a carbon-based conditioning agent, the preparation method of which comprises the following steps:

[0071] The method of Example 1 was followed, except that the mixture was washed with water until neutrality and dried in a desiccator for 12 h to obtain a carbon-based conditioner.

[0072] Comparative Example 4

[0073] This comparative example provides a carbon-based conditioning agent, the preparation method of which comprises the following steps:

[0074] The method of Example 3 was followed, except that the temperature was raised to 600° C. at a rate of 20° C. / min and heated for 1.5 h.

[0075] Comparative Example 5

[0076] This comparative example provides a carbon-based conditioning agent, the preparation method of which comprises the following steps:

[0077] The method of Example 3 was followed, except that the temperature was raised to 1800° C. at a rate of 20° C. / min and heated for 1.5 h.

[0078] Test Case

[0079] Average particle size test

[0080] The particle size was obtained by transmission electron microscopy (measured by TEM ruler), and the average value of the test was taken three times to obtain the average particle size.

[0081] Specific surface area test

[0082] The dynamic nitrogen adsorption specific surface area analyzer was used to perform flow adsorption and measure the specific surface area. The specific method was to adjust the nitrogen pressure to 1.5 kg·cm -2 , adjust the carrier gas flow rate v1 = 5mL·min -1 (Pipeline cleaning), v2=15mL·min -1 (flow rate during the formal test), so that the relative pressure of methanol (p / p0) is stabilized at 0.25; the mass of the carbon-based conditioning agent of the embodiment and the comparative example is weighed, and methane vapor is introduced until the sample mass change is ≤0.5 mg, and the adsorption amount is calculated according to the BET formula.

[0083] Porosity

[0084] The mercury content was determined using a Micromeritics Autopore IV 9500 automatic mercury intrusion porosimeter.

[0085] Average pore size test

[0086] The average pore size is determined by nitrogen adsorption capacity method according to the BJH calculation method (see Petrochemical Analysis Method (RIPP Test Method), RIPP151-90, Science Press, 1990).

[0087] Test of graphite crystal content

[0088] X'Pert PRO MPD instrument was used to perform XRD test, and the graphite (002) interlayer spacing d was first determined. 002 Then substitute into the Mering-Maire formula to calculate:

[0089] G= ;

[0090] Where: G is the graphite crystal content, wt%;

[0091] 0.3440 is the interlayer spacing of non-graphitized carbon, nm;

[0092] 0.3354 is the interlayer spacing of an ideal graphite crystal, which is also 1 / 2 of the c-axis lattice constant of hexagonal graphite, nm;

[0093] d 002 is the interlayer spacing of the (002) crystal plane of carbon material, nm.

[0094] The test results are shown in Table 1;

[0095] Table 1 Performance parameters of carbon-based conditioners

[0096]

[0097] (2) Sludge electroosmosis dehydration process:

[0098] Take 100mL of sludge (from Xiaohongmen Wastewater Treatment Plant of Beijing Drainage Group, with a water content of 97%) in a beaker, add carbon-based conditioning agent, the content of carbon-based conditioning agent is 10wt% based on the mass of sludge dry weight, place the beaker, start the magnetic stirring device, and stir at 900r·min. -1 After stirring for 20 minutes and letting it stand, the conditioned sludge was placed in the cylindrical piston filter press chamber for the electro-osmosis sludge dehydration test, and the mud cake and the anode and cathode filtrate were collected. The mechanical pressure used in the test was 0.5 MPa, the voltage was 55 V, the time was 1 hour, and the current changed continuously as the test progressed.

[0099] Resistivity test

[0100] The resistivity of the carbon-based conditioner was measured using the four-probe method. Four probes were placed lightly on the sample surface at equal intervals (usually 1 mm). The current source was set to output a constant current (50 mA). The voltage (V) was recorded and the resistivity was calculated using the following formula:

[0101] ;

[0102] s, the distance between probes.

[0103] Test of average cathode dehydration rate

[0104] Instantaneous dehydration rate test method: within the i-th time interval Δti (Δt i =t i -t i-1 , t i and t i-1 are the time of the i-th and i-1-th records respectively), and the corresponding cumulative water quality is g1 and g i-1 , then the water quality Δg in this time interval i =g i -g i-1 , instantaneous dehydration rate calculation formula: V i ;

[0105] The calculation formula of average electroosmotic dehydration rate is: ;

[0106] Where: V A is the average electroosmotic dehydration rate; V i is the instantaneous dehydration rate; n is the number of data collection times.

[0107] Testing of moisture content of sludge treated by electric dehydration

[0108] The weight of the sludge after electro-dehydration treatment was recorded as the initial weight. Then, the sludge after electro-dehydration treatment was heated in an oven at 80°C for 5 hours, dried, and cooled to room temperature. The weight of the solid was recorded as the dry weight. Then, the following formula was used to calculate:

[0109] .

[0110] EPS content test

[0111] In this experiment, the filtrates from the cathode and anode were collected and filtered through a 0.45 μm filter membrane. The resulting solution was the dissolved organic matter (DOM) in the sludge, namely EPS. DOM was measured using a Torch combustion automatic sampling analyzer (Teledyne Tekmar, USA).

[0112] The test results are shown in Table 2;

[0113] Table 2 Parameters and performance parameters of the products obtained during the sludge electric dehydration process

[0114]

[0115] (3) Figure 1 is the XRD pattern of the carbon-based conditioning agent of Example 1 and Comparative Example 1, from Figure 1 It can be seen that compared with Comparative Example 1, Example 1 has characteristic diffraction peaks of graphite crystals; Figure 2 is the XRD pattern of the carbon-based conditioning agent of Example 4 and Comparative Example 1, from Figure 2 It can be seen from the figure that compared with comparative example 1, Example 4 has characteristic diffraction peaks of graphite crystals and the peaks are higher than those in Example 1. The XRD curves of Example 1 and Example 4 have two peaks at 26.4 and 43.8, corresponding to the (002) peak and (100) peak of carbon, respectively, indicating that graphite crystals appear in the modified coconut shell charcoal. The peak intensity of the graphite crystals in Example 4 is higher, proving that the mass ratio of coconut shell activated carbon and solid potassium hydroxide can further promote the formation of graphite crystals in coconut shell charcoal.

[0116] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A carbon-based conditioning agent, characterized in that The carbon-based conditioning agent has an average particle size of 15-45 μm and a specific surface area of ​​600-1000 m 2 / g, porosity of 50-90%, and average pore size of 10-60nm; The graphite crystal content is 50-75 wt% based on the mass of the carbon-based conditioning agent; The preparation method of the carbon-based conditioning agent comprises the following steps: The biomass activated carbon and solid alkali are mixed, pyrolyzed in a gas atmosphere containing a crackable carbon source gas to obtain a mixture, and acid-washed to obtain a carbon-based conditioning agent; The pyrolysis conditions include: heating to 800-1500° C. at a rate of 5-20° C. / min for 1-2 hours.

2. The carbon-based conditioning agent according to claim 1, characterized in that The carbon-based conditioning agent has an average particle size of 15-20 μm and a specific surface area of ​​800-1000 m 2 / g, porosity of 60-80%, and average pore size of 10-30nm; The graphite crystal content is 50-70 wt % based on the mass of the carbon-based conditioning agent.

3. A method for preparing the carbon-based conditioning agent according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: The biomass activated carbon and solid alkali are mixed, pyrolyzed in a gas atmosphere containing a crackable carbon source gas to obtain a mixture, and acid-washed to obtain a carbon-based conditioning agent; The pyrolysis conditions include: heating to 800-1500° C. at a rate of 5-20° C. / min for 1-2 hours.

4. The preparation method according to claim 3, characterized in that The crackable carbon source gas includes at least one of alkanes, alkenes, alkynes, and carbon monoxide.

5. The preparation method according to claim 3 or 4, characterized in that The crackable carbon source gas includes at least one of methane, ethylene, propyne and carbon monoxide; And / or, the gas atmosphere further comprises a protective gas, and the volume ratio of the gas containing the crackable carbon source to the protective gas is 1:3-10.

6. The preparation method according to claim 3, characterized in that The mass ratio of the biomass activated carbon to the solid alkali is 1:2-5; And / or, the biomass activated carbon includes at least one of coconut shell activated carbon and straw activated carbon.

7. The preparation method according to claim 6, characterized in that The mass ratio of the biomass activated carbon to the solid alkali is 1:4.5-5.

8. The preparation method according to claim 3, characterized in that The pyrolysis conditions include: a heating rate of 5-10°C / min and a temperature of 900-1000°C.

9. The preparation method according to claim 3, characterized in that The mixture is washed with water until it is neutral and then dried, and then acid-washed. The acid-washed product is washed with water until it is neutral and then dried to obtain a carbon-based conditioner.

10. Use of the carbon-based conditioning agent according to claim 1 or 2, or the carbon-based conditioning agent prepared by the preparation method according to any one of claims 3 to 9, in sludge electric dewatering.

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