CN104998620A - Modified peanut shell biochar/polyaluminium chloride sludge composite adsorption material - Google Patents

Abstract

The invention discloses a modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material, which is prepared from agricultural solid waste peanut shells and polyaluminum chloride sludge from a water supply plant according to the following process: peanut shell modification properties, anaerobic pyrolysis of peanut shells, oxygen supplementation of peanut shell biochar, vacuum acid treatment of peanut shell biochar, modification of polyaluminum chloride sludge, bonding of magnetic magnesium oxide, preparation of adhesives, and preparation of composite adsorption materials. The invention uses organic agricultural solid waste peanut shells and water supply plant sludge as raw materials to prepare a new type of composite adsorption material capable of efficiently adsorbing organic pollutants and phosphorus in water, which not only has the adsorption effect of modified biochar, but also has the function of polychlorination The phosphorus removal ability of aluminum sludge, especially for the deep phosphorus removal of dye-containing wastewater and sewage, has a good removal effect. The source of raw materials is wide and the preparation cost is low. It achieves the purpose of treating waste with waste. A new way of resource utilization of peanut shells and water supply sludge.

Description

A Modified Peanut Shell Biochar/Polyaluminium Chloride Sludge Composite Adsorption Material

technical field

The invention relates to the technical field of sewage treatment by biomass environmental adsorption materials. Specifically relates to a modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material.

Background technique

In recent years, the resource utilization of agricultural solid waste has attracted much attention. As a major economic crop, peanuts are widely planted in our country, and a large number of peanut shells are piled up or burned as agricultural solid waste. This not only causes a waste of resources, but also produces a large amount of smog and CO, CO ₂ and other substances, which endanger the ecological environment. At present, organic agricultural solid waste carbonization technology has attracted more and more attention due to its characteristics of low investment, high benefit, and wide application range. The product of carbonization of organic agricultural solid waste - charcoal particles can be further processed to produce civil charcoal and activated carbon; it can also be applied to farmland as a soil improver to improve the quality of farmland soil. In addition, some scholars have shown that biochar made from organic biomass after carbonization has good adsorption properties for pollutants in the atmosphere, soil and water.

The surface modification of biomass materials is to change the surface properties of biomass materials by physical and chemical methods, change their pore structure, change their surface acidity and alkalinity, or introduce or remove certain functional groups on the surface to make biomass have Special adsorption properties and catalytic properties. Generally, biochar prepared by surface modification has better adsorption performance.

Water supply sludge is a by-product of the coagulation and sedimentation process in water supply plants. Its source is stable and its output is large. Its main components include humus, silicate, organic matter and some metal hydroxides. At present, the most commonly used coagulant in water supply plants is polyaluminum chloride. When polyaluminum chloride is used as a coagulant for coagulation treatment, because the generated water supply sludge contains a large amount of polyaluminum chloride, it is called polyaluminum chloride. Polyaluminum Chloride Sludge. When the polyaluminum chloride sludge containing coagulants such as aluminum salts is discharged into the water body, the deposition of a large amount of aluminum salts will cause harm to aquatic organisms and benthic organisms; and the heavy metals contained in the sludge may also be harmful to groundwater pollution. In order to reduce or even eradicate the environmental damage caused by sludge from water supply plants, scholars at home and abroad have conducted a lot of research on the recycling and reuse of polyaluminum chloride sludge, such as using aluminum-containing sludge as an adsorbent to study its effect on phosphorus in wastewater. Removal and improved reuse of sludge, etc.

Retrieval of relevant literature shows that before the date of this patent application, no similar method of using organic agricultural solid waste as raw material to prepare modified biochar, combined with water supply plant sludge to jointly prepare composite adsorption materials, and used to adsorb organic matter and phosphorus in water has not been found. literature. The invention not only enables the resource utilization of peanut shells, but also achieves the purpose of treating waste with waste.

Contents of the invention

The technical problem to be solved by the present invention is to provide a modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material, which has the high-efficiency adsorption performance of modified biochar on organic matter in water, and also has improved The characteristics of high-efficiency adsorption of phosphorus in water by permanent polyaluminum chloride sludge can be widely used in the removal of organic pollutants and phosphorus in water to achieve the purpose of treating waste with waste.

The technical scheme of the invention is: a modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material, which is prepared by combining agricultural solid waste peanut shells and polyaluminum chloride sludge from a water supply plant.

Further, the described modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material is prepared according to the following process:

(1) Modification of peanut shells: Peanut shells are pulverized into coarse powder by a pulverizer, ground into fine powder by a grinder, added with 5-17% activator relative to the total weight of peanut shells, stirred evenly, pressed into lumps, placed in Heat and steam in a steamer for 2-3 hours, rinse with tap water after cooling to room temperature, filter, and dry until the moisture content is 25-45%;

(2) Anaerobic pyrolysis of peanut shells: the peanut shells treated in step (1) are anaerobically pyrolyzed in a mixed gas with a ratio of _CO2 and CO of 3 to 4:1. The pyrolysis is divided into three stages. The temperature of the first stage is 380-520°C, and the time lasts for 20 to 45 minutes; the temperature of the second stage is 580-720°C, and the time lasts for 20-30 minutes; the temperature of the third stage is 750-880°C, and the time lasts for 15-35 minutes. Obtain peanut shell biochar and by-products, said by-products include organic acid, bio-oil and volatile gas, and keep peanut shell biochar and organic acid for use;

(3) Oxygen supplementation of peanut shell biochar: oxygen supplementation is divided into two stages. The first stage is to add 1.5-2.0% oxygen supplement compound to the peanut shell biochar relative to the total weight of peanut shell biochar, at 200-340 Heating under the temperature condition of ℃, the oxygen supplement compound is sodium hypochlorite and hydrogen peroxide, the molar ratio between the two is 1:1, the second stage of oxygen supplement is to put the peanut shell biochar after the first stage of oxygen supplement at 12～ Under the condition of 35°C, low-temperature plasma treatment is carried out, and the low-temperature plasma is oxygen, which partially oxygenates the peanut shell biochar;

(4) Vacuum acid treatment of peanut shell biochar: impregnate the by-product organic acid produced in the pyrolysis process of step (2) under vacuum conditions through two-stage oxygen supplemented peanut shell biochar. Adjust the concentration to 12-30%, control the pH at 6.0-7.0, and soak for 24-48 hours, then continue to filter and dry under vacuum conditions to obtain the modified peanut shell biochar;

(5) Modification of polyaluminum chloride sludge: dry the polyaluminum chloride sludge from the water supply plant, crush it through a 20-mesh sieve, and put it into a pyrolysis reactor for aerobic treatment at 300-500°C for 1-3 hours. Then cool down at a rate of 2-3°C/min, and perform anaerobic treatment at the same time until the temperature drops to 150-200°C, stop cooling, continue constant temperature treatment for 0.5-1h, and then cool to room temperature under the condition of isolating oxygen. Obtain modified microporous polyaluminum chloride sludge;

(6) Bonding magnetic magnesia: Add 0.002-0.015% magnetic particle magnesia to the modified microporous polyaluminum chloride sludge, mix well, and put it into a high-temperature heating device to heat up at a rate of 50-100°C/min. Heating rate heating, when the temperature rises to 700 ~ 850 ℃, isolated from the air to continue processing for 5 ~ 8h;

(7) Preparation of adhesive: Weigh 5% carboxymethyl cellulose and place it in a beaker, add distilled water in equal proportions, heat and gelatinize under constant stirring, and cool to room temperature to obtain an adhesive;

(8) Preparation of composite adsorption material: The prepared modified peanut shell biochar, modified microporous polyaluminum chloride sludge, adhesive, and additives were mixed in a ratio of 3:2:(0.05～0.06):(0.01～ 0.012) is mixed uniformly, molded by a molding machine, heated in a high-temperature heating device at 100-200°C for 1-4 hours, and cooled to normal temperature to obtain a composite adsorption material.

Further, the activator is 40% zinc chloride, and the activator can change the surface activity of peanut shells.

Further, the admixture is a modified polyacrylonitrile fiber, and its specifications are: the length is 1-15 mm, and the diameter is 1-50 μm.

Further, the shape of the prepared composite adsorption material is granular, columnar or spherical.

The beneficial effects of the present invention are:

(1) The composite adsorption material of the present invention not only has the adsorption effect of modified biochar, but also has the phosphorus removal ability of polyaluminum chloride sludge, especially has a good removal of dye-containing wastewater and sewage deep phosphorus removal Effect;

(2) The present invention uses organic agricultural solid waste peanut shells and water supply plant sludge as raw materials to prepare a new type of composite adsorption material with high-efficiency adsorption of organic pollutants and phosphorus in water, which is used for water treatment and achieves the goal of treating waste with waste The purpose is not only to effectively control environmental pollution, but also to open up a new way of resource utilization of peanut shells and water supply sludge;

(3) The composite adsorption material of the present invention has wide sources of raw materials, low preparation cost, convenient use, high efficiency, environmental protection, low cost and strong applicability.

Detailed ways

Example 1:

A modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material is prepared by combining agricultural solid waste peanut shells and polyaluminum chloride sludge from a water supply plant. Described a kind of modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material is prepared according to the following process:

(1) Modification of peanut shells: peanut shells are pulverized into coarse powder by a pulverizer, ground into fine powder by a grinder, and stirred evenly by adding 5% activator relative to the total weight of peanut shells, and the activator is 40% zinc chloride , the activator can change the surface activity of peanut shells, press them into agglomerates, put them in a steamer and steam them for 2 hours, rinse them with tap water after cooling to room temperature, filter, and dry until the moisture content is 25%;

(2) Anaerobic pyrolysis of peanut shells: the peanut shells treated in step (1) are anaerobically pyrolyzed in a mixture of _CO2 and CO ratio of 3:1. The pyrolysis is divided into three stages, the first stage The temperature is 380°C for 20 minutes, the second stage temperature is 580°C and the time lasts 20 minutes; the third stage temperature is 750°C and the time lasts 15 minutes to obtain peanut shell biochar and by-products, which include Organic acid, bio-oil and volatile gas, reserve peanut shell biochar and organic acid for later use;

(3) Oxygen supplementation of peanut shell biochar: oxygen supplementation is divided into two stages. The first stage is to add 1.5% oxygen supplement compound relative to the total weight of peanut shell biochar to the peanut shell biochar. Under heating, the oxygen supplement compound is sodium hypochlorite and hydrogen peroxide, and the molar ratio between the two is 1:1. The second stage of oxygen supplement is to carry out the peanut shell biochar that has undergone the first stage of oxygen supplement at 12°C. Low-temperature plasma treatment, the low-temperature plasma is oxygen, and partially oxygenates the peanut shell biochar;

(4) Vacuum acid treatment of peanut shell biochar: impregnate the by-product organic acid produced in the pyrolysis process of step (2) under vacuum conditions through two-stage oxygen supplemented peanut shell biochar. Adjust the concentration to 12%, control the pH at 6.0, and soak for 24 hours, then continue to filter and dry under vacuum conditions to obtain the modified peanut shell biochar;

(5) Modification of polyaluminum chloride sludge: dry the polyaluminum chloride sludge from the water supply plant, crush it through a 20-mesh sieve, put it into a pyrolysis reactor for aerobic treatment at 300°C for 1 hour, and then heat it at 2°C Cool at a rate of 1/min, and perform anaerobic treatment until the temperature drops to 150°C, stop cooling, continue constant temperature treatment for 0.5h, and then cool to room temperature under the condition of oxygen isolation, that is, the modified microporous polyaluminum chloride sludge;

(6) Bonding magnetic magnesia: the modified microporous polyaluminum chloride sludge is mixed with 0.002% magnetic particle magnesia, mixed evenly, put into high-temperature heating equipment and heated at a heating rate of 50°C/min, When the temperature rises to 700°C, continue the treatment for 5 hours without air;

(7) Preparation of adhesive: Weigh 5% carboxymethyl cellulose and place it in a beaker, add distilled water in equal proportions, heat and gelatinize under constant stirring, and cool to room temperature to obtain an adhesive;

(8) Preparation of composite adsorption material: mix the obtained modified peanut shell biochar, modified microporous polyaluminum chloride sludge, adhesive, and admixture in a ratio of 3:2:0.05:0.01, The admixture is a modified polyacrylonitrile fiber, and its specifications are: the length is 1 mm, the diameter is 1 μm, and it is formed by a molding machine, and heated in a high-temperature heating device at 100 ° C for 1 hour, and cooled to room temperature to obtain a composite adsorption material , the shape of the prepared composite adsorption material is granular, columnar or spherical.

Example 2:

A modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material is prepared by combining agricultural solid waste peanut shells and polyaluminum chloride sludge from a water supply plant. Described a kind of modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material is prepared according to the following process:

(1) Peanut shell modification: Peanut shells are pulverized into coarse powder by a pulverizer, ground into fine powder by a grinder, and stirred evenly by adding 11% of an activator relative to the total weight of the peanut shell, and the activator is 40% zinc chloride , the activator can change the surface activity of peanut shells, press them into lumps, put them in a steamer and steam them for 2.5 hours, rinse them with tap water after cooling to room temperature, filter, and dry until the moisture content is 35%;

(2) Anaerobic pyrolysis of peanut shells: the peanut shells treated in step (1) are anaerobically pyrolyzed in a mixed gas with a _CO ratio of 3.5:1. The pyrolysis is divided into three stages, the first stage The temperature is 450°C for 32.5 minutes, the second stage temperature is 650°C and the time lasts 25 minutes; the third stage temperature is 815°C and the time lasts 25 minutes to obtain peanut shell biochar and by-products, which include Organic acid, bio-oil and volatile gas, reserve peanut shell biochar and organic acid for later use;

(3) Oxygen supplementation of peanut shell biochar: oxygen supplementation is divided into two stages. The first stage is to add 1.75% oxygen supplement compound to the peanut shell biochar relative to the total weight of peanut shell biochar. Under heating, the oxygen supplement compound is sodium hypochlorite and hydrogen peroxide, and the molar ratio between the two is 1:1. The second stage of oxygen supplement is to carry out the peanut shell biochar that has undergone the first stage of oxygen supplement at 23.5 ° C. Low-temperature plasma treatment, the low-temperature plasma is oxygen, and partially oxygenates the peanut shell biochar;

(4) Vacuum acid treatment of peanut shell biochar: impregnate the by-product organic acid produced in the pyrolysis process of step (2) under vacuum conditions through two-stage oxygen supplemented peanut shell biochar. Adjust the concentration to 21%, control the pH at 6.5, and soak for 36 hours, then continue to filter and dry under vacuum conditions to obtain the modified peanut shell biochar;

(5) Modification of polyaluminum chloride sludge: dry the polyaluminum chloride sludge from the water supply plant, crush it through a 20-mesh sieve, put it into a pyrolysis reactor for aerobic treatment at 400°C for 2 hours, and then heat it at 2.5°C Cool at a rate of 1/min, and perform anaerobic treatment until the temperature drops to 175°C, stop cooling, continue constant temperature treatment for 0.75h, and then cool to room temperature under the condition of oxygen isolation, that is, the modified microporous polyaluminum chloride is prepared sludge;

(6) Bonding magnetic magnesia: the modified microporous polyaluminum chloride sludge is mixed with 0.0085% magnetic particle magnesia, mixed evenly, put into high-temperature heating equipment and heated at a heating rate of 75°C/min, When the temperature rises to 775°C, continue the treatment for 6.5 hours without air;

(7) Preparation of adhesive: Weigh 5% carboxymethyl cellulose and place it in a beaker, add distilled water in equal proportions, heat and gelatinize under constant stirring, and cool to room temperature to obtain an adhesive;

(8) Preparation of composite adsorption material: mix the obtained modified peanut shell biochar, modified microporous polyaluminum chloride sludge, adhesive, and admixture in a ratio of 3:2:0.055:0.011, The admixture is a modified polyacrylonitrile fiber, and its specification is: length is 8mm, diameter is 25.5μm, shaped by a molding machine, heated in a high-temperature heating device at 150°C for 2.5h, and cooled to room temperature to obtain a composite As for the adsorption material, the composite adsorption material is in the shape of granules, columns or spheres.

Example 3:

A modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material is prepared by combining agricultural solid waste peanut shells and polyaluminum chloride sludge from a water supply plant. Described a kind of modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material is prepared according to the following process:

(1) Peanut shell modification: Peanut shells are crushed into coarse powder by a pulverizer, ground into fine powder by a grinder, and stirred evenly by adding 17% of an activator relative to the total weight of the peanut shell, and the activator is 40% zinc chloride , the activator can change the surface activity of peanut shells, press them into lumps, put them in a steamer and steam them with steam for 3 hours, rinse them with tap water after cooling to room temperature, filter, and dry until the moisture content is 45%;

(2) Anaerobic pyrolysis of peanut shells: the peanut shells treated in step (1) are anaerobically pyrolyzed in a mixture of _CO2 and CO ratio of 4:1. The pyrolysis is divided into three stages, the first stage The temperature is 520°C for 45 minutes, the second stage temperature is 720°C and the time lasts 30 minutes; the third stage temperature is 880°C and the time lasts 35 minutes to obtain peanut shell biochar and by-products, which include Organic acid, bio-oil and volatile gas, reserve peanut shell biochar and organic acid for later use;

(3) Oxygen supplementation of peanut shell biochar: oxygen supplementation is divided into two stages. The first stage is to add 2.0% oxygen supplement compound to the peanut shell biochar relative to the total weight of peanut shell biochar. Under heating, the oxygen supplement compound is sodium hypochlorite and hydrogen peroxide, and the molar ratio between the two is 1:1. The second stage of oxygen supplement is to carry out the peanut shell biochar that has undergone the first stage of oxygen supplement at 35°C. Low-temperature plasma treatment, the low-temperature plasma is oxygen, and partially oxygenates the peanut shell biochar;

(4) Vacuum acid treatment of peanut shell biochar: impregnate the by-product organic acid produced in the pyrolysis process of step (2) under vacuum conditions through two-stage oxygen supplemented peanut shell biochar. Adjust the concentration to 30%, control the pH at 7.0, and soak for 48 hours, then continue to filter and dry under vacuum conditions to obtain the modified peanut shell biochar;

(5) Modification of polyaluminum chloride sludge: dry the polyaluminum chloride sludge from the water supply plant, crush it through a 20-mesh sieve, put it into a pyrolysis reactor for aerobic treatment at 500°C for 3 hours, and then heat it at 3°C Cool at a rate of 1/min, and perform anaerobic treatment until the temperature drops to 200°C, stop cooling, continue constant temperature treatment for 1 hour, and then cool to room temperature under the condition of cutting off oxygen, that is, the modified microporous polyaluminum chloride pollution is obtained mud;

(6) Joining magnetic magnesia: the modified microporous polyaluminum chloride sludge is mixed with 0.015% magnetic particle magnesia, mixed evenly, put into high-temperature heating equipment and heated at a heating rate of 100°C/min, When the temperature rises to 850°C, continue the treatment for 8 hours without air;

(7) Preparation of adhesive: Weigh 5% carboxymethyl cellulose and place it in a beaker, add distilled water in equal proportions, heat and gelatinize under constant stirring, and cool to room temperature to obtain an adhesive;

(8) Preparation of composite adsorption material: mix the prepared modified peanut shell biochar, modified microporous polyaluminum chloride sludge, adhesive, and admixture in a ratio of 3:2:0.06:0.012, The admixture is a modified polyacrylonitrile fiber, and its specification is: the length is 15mm, the diameter is 50μm, it is shaped by a molding machine, heated at 200°C for 4 hours in a high-temperature heating device, and cooled to room temperature to obtain a composite adsorption material , the shape of the prepared composite adsorption material is granular, columnar or spherical.

Specific test example:

1. The modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material prepared in Example 1 is dropped into the phosphorus solution that the initial concentration is 100mg/L reactive brilliant blue X～BR and 5mg/L, the composite adsorption material The dosage was 1.2g/L, and after 2 hours of constant temperature oscillation at 100r/min, the removal rates of reactive brilliant blue X-BR and phosphorus in the solution reached 83.74% and 79.78%, respectively.

2. The modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material prepared in Example 2 is put into the phosphorus solution that the initial concentration is 100mg/L reactive brilliant blue X～BR and 5mg/L, and the composite adsorption material The dosage was 1.2g/L, and after 2 hours of constant temperature oscillation at 100r/min, the removal rates of reactive brilliant blue X-BR and phosphorus in the solution reached 87.25% and 85.70%, respectively.

3. The modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material prepared in Example 3 is dropped into the phosphorus solution that the initial concentration is 100mg/L reactive brilliant blue X～BR and 5mg/L, the composite adsorption material The dosage was 1.2g/L, and after 2 hours of constant temperature oscillation at 100r/min, the removal rates of reactive brilliant blue X-BR and phosphorus in the solution reached 90.43% and 87.0%, respectively.

It can be seen from the above experiments that the modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material of the present invention has a good adsorption effect and a high removal rate of phosphorus.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (5)

1. A modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material, characterized in that: the composite adsorption material is made by combining agricultural solid waste peanut shells and polyaluminum chloride sludge from a water supply plant. 2. a kind of modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material according to claim 1 is characterized in that it is prepared by the following process: (1) Modification of peanut shells: Peanut shells are pulverized by a pulverizer, ground by a grinder, added with an activator of 5-17% relative to the total weight of peanut shells, stirred evenly, pressed, placed on a steamer and steamed for 2 ~3h, rinse with tap water after cooling to room temperature; (2) Anaerobic pyrolysis of peanut shells: the peanut shells treated in step (1) are anaerobically pyrolyzed in a mixed gas with a ratio of _CO2 and CO of 3 to 4:1. The pyrolysis is divided into three stages. The temperature of the first stage is 380-520°C, and the time lasts for 20 to 45 minutes; the temperature of the second stage is 580-720°C, and the time lasts for 20-30 minutes; the temperature of the third stage is 750-880°C, and the time lasts for 15-35 minutes. Obtain peanut shell biochar and by-products, which include organic acids, bio-oils and volatile gases; (3) Oxygen supplementation of peanut shell biochar: oxygen supplementation is divided into two stages. The first stage is to add 1.5-2.0% oxygen supplement compound to the peanut shell biochar relative to the total weight of peanut shell biochar, at 200-340 ℃, the oxygen supplement compound is sodium hypochlorite and hydrogen peroxide, and the oxygen supplement in the second stage is to conduct low-temperature plasma treatment on the peanut shell biochar that has undergone the oxygen supplement in the first stage under the condition of 12-35 °C. The low-temperature plasma is oxygen, which partially oxygenates the peanut shell biochar; (4) Vacuum acid treatment of peanut shell biochar: The peanut shell biochar that has undergone two-stage oxygenation is impregnated with the by-product organic acid produced in the pyrolysis process of step (2) under vacuum conditions, and the pH is controlled at 6.0-7.0. The time is 24 to 48 hours, and then continue to filter and dry under vacuum conditions to obtain modified peanut shell biochar; (5) Modification of polyaluminum chloride sludge: dry the polyaluminum chloride sludge from the water supply plant, crush it through a 20-mesh sieve, and put it into a pyrolysis reactor for aerobic treatment at 300-500°C for 1-3 hours. Then cool down at a rate of 2-3°C/min, and carry out anaerobic treatment at the same time until the temperature drops to 150-200°C, stop cooling, continue to treat for 0.5-1h, and then cool to room temperature to obtain modified microporous polymeric chlorine Aluminum sludge; (6) Bonding magnetic magnesia: Add 0.002-0.015% magnetic particle magnesia to the modified microporous polyaluminum chloride sludge, mix well, and put it into a high-temperature heating device to heat up at a rate of 50-100°C/min. Heating rate heating, when the temperature rises to 700 ~ 850 ℃, isolated from the air to continue processing for 5 ~ 8h; (7) Preparation of adhesive: Weigh 5% carboxymethyl cellulose and place it in a beaker, add distilled water in equal proportions, heat and gelatinize under constant stirring, and cool to room temperature to obtain an adhesive; (8) Preparation of composite adsorption material: The prepared modified peanut shell biochar, modified microporous polyaluminum chloride sludge, adhesive, and additives were mixed in a ratio of 3:2:(0.05～0.06):(0.01～ 0.012) in a proportion that is uniformly mixed and molded, heated at 100-200° C. for 1-4 hours in a high-temperature heating device, and cooled to obtain a composite adsorption material. 3. A modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material according to claim 2, characterized in that the activator is 40% zinc chloride. 4. A modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material according to claim 2, characterized in that the admixture is a modified polyacrylonitrile fiber. 5. A modified peanut shell biochar/polyaluminum chloride sludge composite adsorption material according to claim 2, characterized in that the composite adsorption material obtained is granular, columnar or spherical in shape.