Aluminum matrix composite for sediment remediation

Abstract

The application discloses an aluminum-based composite material for bottom sediment repair, which is used for covering bottom sediment, fixing phosphorus and organic matters released in the bottom sediment, and is prepared by mixing and ball-milling Al powder and acid-treated activated carbon under inert gas conditions, and the weight percentage of the acid-treated activated carbon and the Al powder is 4-6:1; the aluminum-based composite material put into the bottom sediment forms a local alkaline environment, continuously fixes the released phosphorus in the bottom sediment through active zero-valent aluminum which is continuously dissolved and does not passivate, and adsorbs and decomposes organic matters in the bottom sediment through activated carbon with a large specific surface area. + The dense oxide film formed after the aluminum powder meets water is dissolved to expose the zero-valent aluminum inside the oxide film, then a local alkaline environment formed around the aluminum-based composite material through the galvanic cathode effect continuously promotes the activation of the zero-valent aluminum in the inner layer of the aluminum powder, and the activated zero-valent aluminum forms flocculation and precipitation with the endogenous phosphorus released in the bottom sediment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water pollution treatment, in particular to an aluminum-based composite material for sediment remediation. BACKGROUND

[0002] Sediment is an important part of natural water ecosystem and a main storage place of various pollutants. A large amount of phosphorus-containing pollutants and organic pollutants are deposited in the sediment of polluted rivers and lakes. The control of exogenous pollutants and the treatment of water bodies have achieved certain results, but the sediment continuously releases endogenous pollutants towards the overlying water body, and the continuous release of endogenous pollutants in the sediment has become a major cause affecting the water environment.

[0003] The existing in-situ remediation technologies for sediment include physical remediation, biological remediation and chemical remediation. The physical remediation is difficult to meet the requirements in energy consumption and treatment effect; the biological remediation has a long cycle and is greatly affected by environmental factors; and the chemical remediation has a quick effect and a remarkable remediation effect, but the iron salt material in the chemical remediation agent easily causes black odor and increases the turbidity of the water body, and the calcium salt material easily greatly increases the alkalinity of the water body, affecting the ecological environment of the water body.

[0004] Aluminum is abundant in nature, easy to obtain, and Al 3+ has good phosphorus fixation capacity. However, when aluminum powder directly contacts with water, a dense oxide film is quickly formed on the surface of the aluminum powder, and the zero-valent aluminum inside the oxide film cannot continuously react and dissolve due to the existence of the oxide film, resulting in the failure of the phosphorus fixation capacity of the aluminum powder.

[0005] At present, the common method for removing the oxide film on the surface of aluminum is pickling and mechanical treatment, but the treated aluminum usually still needs to be continuously active under strong acidic or alkaline conditions (pH < 4 or pH > 10), and the continuous acidic or alkaline conditions cannot be realized in actual engineering applications. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides an aluminum-based composite material for sediment remediation. Through the galvanic cathodic effect generated by the aluminum-based composite material in the sediment, a local alkaline environment is formed, and the active zero-valent aluminum which continuously dissolves and does not passivate is used to continuously fix the phosphorus released in the sediment.

[0007] In order to achieve the above-mentioned purpose, the application designs an aluminum-based composite material for sediment remediation, which is used for covering sediment, fixing phosphorus and organic matter released in the sediment, and has the particularity that: the aluminum-based composite material is prepared by mixing and ball milling Al powder and acid-treated activated carbon under inert gas conditions, and the weight percentage of the acid-treated activated carbon and the Al powder is 4-6:1; the aluminum-based composite material put into the sediment forms a local alkaline environment, continuously fixes the phosphorus released in the sediment through the active zero-valent aluminum which continuously dissolves and does not passivate, and adsorbs and decomposes the organic matter in the sediment through the activated carbon with a large specific surface area.

[0008] Further, the particle size of the Al powder before ball milling is 100-2000 mesh.

[0009] Further, the activated carbon is selected from one or more of coconut shell activated carbon, wooden activated carbon, nut shell activated carbon and coal activated carbon.

[0010] Further, the inert gas is selected from one or more of nitrogen, argon and helium.

[0011] Further, the aluminum-based composite material is mixed and ball milled by a planetary ball mill, the rotation speed of the ball mill is 200-400 r / min, and the ball milling time is 4-8 h.

[0012] Further, the ball milling bead in the ball mill has a particle size of 6-20 mm.

[0013] Further, the ball milling bead has a particle size of 6 mm, 10 mm and 15 mm respectively, and the corresponding ball milling bead ratio is 15:5:1.

[0014] Further, the ball milling bead is made of one or more of zirconia, agate, corundum and stainless steel.

[0015] Further, the dosage of the aluminum-based composite material put into the sediment is 1-50 g / kg.

[0016] Further, the phosphorus released in the sediment includes combined phosphorus, exchangeable phosphorus, occluded phosphorus, authigenic calcium phosphorus, detrital phosphorus and organic phosphorus, and the organic matter released in the sediment includes tetrachloroethylene, dichlorophenol and p-nitrophenol.

[0017] The principle that the aluminum-based composite material designed by the application can continuously fix the phosphorus released in the sediment is as follows:

[0018] 1. Through mixing and ball milling, the Al powder collides with the activated carbon and the ball milling bead at high speed, the collision destroys the passivation layer on the surface of the Al powder, and exposes fresh active zero-valent aluminum, so as to ensure that the Al powder put into the sediment has activity;

[0019] 2. When an active aluminum-based composite material is added to the bottom mud, the aluminum powder reacts with water to rapidly form a dense oxide film on its surface. A certain amount of H2 is released from the hydrolysis of the acid-treated activated carbon. + Dissolve the oxide film on the aluminum surface to leach Al. 3+ The dissolved Al 3+ It forms flocculation and precipitation with the endogenous phosphorus released from the sediment, which plays a role in fixing the endogenous phosphorus in the sediment. At the same time, the aluminum oxide film on the surface dissolves and exposes the active zero-valent aluminum inside.

[0020] 3. The active zero-valent aluminum inside the oxide film and the activated carbon form a microscopic corrosion galvanic cell in the aqueous solution. The active zero-valent aluminum acts as the anode, gradually dissolving and releasing electrons. The activated carbon material has a strong electron transfer ability, and as the cathode, it transfers the electrons released by the zero-valent aluminum to the surface of the activated carbon, where a hydrolysis reaction occurs, producing OH-. - OH - This process raises the pH level on the activated carbon surface, creating a localized alkaline environment around the aluminum-based composite material (a phenomenon known as the "galvanic cathode effect"). This promotes the activation of zero-valent aluminum in the inner Al layer. The activated zero-valent aluminum then reacts with endogenous phosphorus released from the sediment in this localized alkaline environment to form flocculation and precipitation, thus controlling the endogenous phosphorus in the sediment. Furthermore, the activated zero-valent aluminum has a greater potential difference with the activated carbon, resulting in the generation of more OH- ions on the activated carbon surface, which acts as the cathode. - It can continuously promote the activation of zero-valent aluminum in the inner layer of Al, and continuously form flocculation and precipitation with the endogenous phosphorus released in the sediment, thereby playing a role in continuously controlling the endogenous phosphorus in the sediment.

[0021] The principle behind the aluminum-based composite material designed in the above technical solution, which can continuously adsorb and decompose organic matter in the sediment, is as follows:

[0022] 1. Activated carbon can adsorb organic pollutants in water by utilizing its large specific surface area.

[0023] 2. The pores of activated carbon can provide a habitat for microorganisms in the sediment, forming a biological activated carbon adsorption membrane. Through the anaerobic layer microorganisms inside the biofilm, the difficult-to-decompose large-molecule organic matter in the sediment is converted into easily degradable small-molecule organic matter. Through the aerobic layer microorganisms outside the biofilm, the easily degradable small-molecule organic matter in the sediment is converted into CO2 and H2O, and inorganic phosphorus in the wastewater is converted into adenosine triphosphate in the cells.

[0024] The advantages of this invention are:

[0025] 1. This invention first utilizes a certain amount of H produced by the hydrolysis of acid-treated activated carbon. +The dense oxide film formed after the aluminum powder meets water is dissolved, and the zero-valent aluminum inside the oxide film is exposed; then, the local alkaline environment formed around the aluminum-based composite material through the galvanic cathode effect continuously promotes the activation of the zero-valent aluminum in the inner layer of the aluminum powder, effectively solving the practical problem of poor activation sustainability of zero-valent aluminum when the aluminum-based composite material is applied to sediment remediation;

[0026] 2、The present application not only utilizes the rich functional groups on the surface of activated carbon to alleviate the PH value in water, but also utilizes the hydrolysis product of aluminum powder to stabilize the PH value in water, so that the designed aluminum-based composite material can effectively maintain the solution PH value while treating sediment pollutants, without increasing the alkalinity of the water body;

[0027] 3、The activated carbon with a large specific surface area in the present application can not only adsorb organic pollutants in water, but also can convert and degrade organic matter;

[0028] 4、The activated carbon and aluminum powder treated by acid in the present application are industrial-grade raw materials, which are low in price and easy to obtain, and can be used on a large scale;

[0029] 5、The aluminum-based composite material in the present application is prepared by mixing and ball milling under inert gas conditions, and the preparation method is simple, the production conditions are easy to achieve, and it is suitable for industrial production;

[0030] The H+ produced by the acid-treated activated carbon in the aluminum-based composite material for sediment remediation in the present application is used to dissolve the dense oxide film formed after the aluminum powder meets water, and the zero-valent aluminum inside the oxide film is exposed; + The dense oxide film formed after the aluminum powder meets water is dissolved, and the zero-valent aluminum inside the oxide film is exposed; through the galvanic cathode effect, a local alkaline environment is formed around the aluminum-based composite material, which continuously promotes the activation of the zero-valent aluminum in the inner layer of the aluminum powder, and the activated zero-valent aluminum and the endogenous phosphorus released from the sediment form a flocculation precipitate in an alkaline environment, thereby continuously fixing the phosphorus released from the sediment; and the activated carbon with a large specific surface area continuously adsorbs and decomposes organic matter in the sediment. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The mechanism diagram for the present application to continuously fix the phosphorus released from the sediment;

[0032] Figure 2 The scanning electron microscope image of the present application prepared into granules;

[0033] Figure 3 The schematic diagram of the sediment remediation device applied in the embodiment of the present application;

[0034] Figure 4-1 The total phosphorus concentration change diagram in the comparative example;

[0035] Figure 4-2 The total phosphorus concentration change diagram applied in the embodiment of the present application;

[0036] Figure 5-1 The light wave number change graph in the application applied in the example;

[0037] Figure 5-2 The light wave number change graph in the application applied in the example;

[0038] Figure 6-1 The organic pollutant dichlorophenol concentration change graph in the application applied in the example;

[0039] Figure 6-2 The organic pollutant dichlorophenol concentration change graph in the application applied in the example. DETAILED DESCRIPTION

[0040] The application will be further described in detail below in combination with the drawings and specific examples.

[0041] In the description of the application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0042] The aluminum-based composite material for sediment remediation is used for covering the sediment, fixing the phosphorus and organic matter released in the sediment, and is prepared by mixing and ball milling Al powder and acid-treated activated carbon (AAC) under inert gas conditions, and the weight percentage of the acid-treated activated carbon and the Al powder is 4-6:1; the aluminum-based composite material put into the sediment forms a local alkaline environment, continuously fixes the phosphorus released in the sediment through the active zero-valent aluminum which continuously dissolves and does not passivate, and adsorbs and decomposes the organic matter in the sediment through the activated carbon with a large specific surface area.

[0043] The particle size of the Al powder before ball milling is 100-2000 mesh. The Al powder with too small particle size has too high activity, and there is a risk in the storage and transportation process, and the Al powder with too large particle size has low reaction activity and is not easy to activate.

[0044] The activated carbon is selected from one or more of coconut shell activated carbon, wooden activated carbon, fruit shell activated carbon and coal-based activated carbon. Such activated carbon materials have a large specific surface area and rich functional groups.

[0045] The inert gas is selected from one or more of nitrogen, argon and helium. In addition, the aluminum-based composite material after ball milling needs to be collected and stored in an inert gas atmosphere and sealed for preservation.

[0046] The aluminum-based composite material is mixed and ball-milled using a planetary ball mill with a rotation speed of 200–400 r / min and a milling time of 4–8 h.

[0047] The ball mill beads in the ball mill have a particle size of 6–20 mm.

[0048] The grinding beads have particle sizes of 6mm, 10mm, and 15mm, and the corresponding grinding bead ratio is 15:5:1.

[0049] The grinding beads are made of one or more of the following materials: zirconium oxide, agate, corundum, and stainless steel.

[0050] The activated carbon and aluminum powder used in this invention are both industrial-grade raw materials, which are inexpensive and readily available, and can be used on a large scale. Furthermore, the aluminum-based composite material is prepared by ball milling under inert gas conditions, which is a simple preparation method and easy to achieve production conditions, making it suitable for industrial production.

[0051] The amount of the aluminum-based composite material added to the sediment is 1-50 g / kg.

[0052] The phosphorus released from the sediment includes bound phosphorus, exchangeable phosphorus, occluded phosphorus, autogenous calcium phosphorus, detrital phosphorus, and organic phosphorus. The organic matter in the sediment includes tetrachloroethylene, dichlorophenol, and p-nitrophenol.

[0053] The principle behind the aluminum-based composite material designed in the above technical solution for continuously immobilizing phosphorus released from the sediment is as follows:

[0054] First, through ball milling, aluminum powder collides at high speed with activated carbon and milling beads. The collision destroys the passivation layer on the surface of the aluminum powder, exposing fresh, active zero-valent aluminum, ensuring that the aluminum powder added to the bottom sediment is active.

[0055] Secondly, when an active aluminum-based composite material is added to the bottom mud, the aluminum powder quickly forms a dense oxide film on its surface upon contact with water. A certain amount of H2 is released from the hydrolysis of the acid-treated activated carbon. + Dissolve the oxide film on the aluminum surface to leach out Al. 3+ As shown in formulas 1 and 2. The dissolved Al 3+ It forms flocculation and precipitation with endogenous phosphorus released from the sediment, thus fixing the endogenous phosphorus in the sediment. At the same time, the aluminum oxide film on the surface dissolves, exposing the active zero-valent aluminum inside. The mechanism is as follows: Figure 1 As shown.

[0056] Anode reaction: Al₂O₃ + H₂ + =2Al 3+ +3H₂O, Al-3e - =Al 3+ Formula 1 Cathode reaction: 2H+ +2e - = H2 Formula 2

[0057] Third, the active zero-valent aluminum inside the oxide film and the activated carbon form a micro-corrosion primary cell in the aqueous solution. The active zero-valent aluminum gradually dissolves and releases electrons as an anode, while the activated carbon material has a strong electron transfer ability. The activated carbon transfers the electrons released by the zero-valent aluminum to the surface of the activated carbon as a cathode, and then a hydrolysis reaction occurs, generating OH - , OH - which promotes the increase of the PH value on the surface of the activated carbon, thereby forming a local alkaline environment around the aluminum-based composite material (this phenomenon is the "Galvanic cathode effect"), which promotes the activation of the zero-valent aluminum in the inner layer of Al, as shown in Formulas 3-4. The activated zero-valent aluminum and the endogenous phosphorus released from the sediment form a flocculation and precipitation in the local alkaline environment, which plays a role in controlling the endogenous phosphorus in the sediment, as shown in Formula 5. The activated zero-valent aluminum and the activated carbon have a greater potential difference, and the surface of the activated carbon as a cathode will generate more OH - , which can continuously promote the activation of the zero-valent aluminum in the inner layer of Al and continuously form a flocculation and precipitation with the endogenous phosphorus released from the sediment, thereby playing a role in continuously controlling the endogenous phosphorus in the sediment, as shown in Figure 1 .

[0058] Anode reaction: Al - 3e - = Al 3+ E 0 (Al 3+ / Al) = -1.66 V Formula 3

[0059] Cathode reaction: 2H2O + 2e - = H2 + 2OH - Formula 4

[0060] nAl 3+ + PO4 3- + (3n-3)OH - = Al n PO4(OH) 3n -3 Formula 5

[0061] The above local alkaline environment exists in the micro-corrosion primary cell reaction system and has little effect on the PH of the sediment.

[0062] In the above technical solution, the aluminum-based composite material designed can continuously adsorb and decompose the organic matter released from the sediment, and the principle is as follows:

[0063] First, the activated carbon can adsorb organic pollutants in water by using its large specific surface area.

[0064] Secondly, the pores of activated carbon can provide a habitat for microorganisms in the sediment, forming a biological activated carbon adsorption membrane. Through the aerobic layer outside the biofilm, microorganisms convert easily decomposed small-molecule organic matter in the sediment into CO2 and H2O, and convert inorganic phosphorus in the sewage into adenosine triphosphate in the cells. Through the anaerobic layer outside the biofilm, microorganisms convert difficult-to-decompose large-molecule organic matter in the sediment into easily degradable small-molecule organic matter.

[0065] This invention first utilizes H2 produced by the hydrolysis of acid-treated activated carbon. + The dense oxide film formed when aluminum powder comes into contact with water is dissolved, exposing the zero-valent aluminum inside the oxide film; then, through the galvanic cathodic effect, a local alkaline environment is formed around the aluminum-based composite material, which continuously promotes the activation of the zero-valent aluminum in the inner layer of the aluminum powder, effectively solving the practical problem of poor activation sustainability of zero-valent aluminum when aluminum-based composite materials are used for sediment remediation.

[0066] The specific implementation method is as follows:

[0067] Devices for remediating sediment using acrylic glass as the raw material, such as... Figure 3 As shown, the cylindrical section of the sediment remediation device is divided into two parts: a sediment section (12 cm high) and an overlying water section (16 cm high), with an inner diameter of 8 cm. The sediment section is further divided into three zones from top to bottom: surface layer, transition layer, and bottom layer. The overlying water section is also divided into two zones from top to bottom: upper water and lower water. Sediment (1 kg, 70% water content) is filled into the sediment section according to the designated zones, and lake water (0.8 L) is filled into the overlying water section. To simulate natural conditions, the device is not sealed. Sampling ports are set up in the upper water, lower water, surface layer, transition layer, and bottom layer, and each sampling port is connected to a Rizhon sampler.

[0068] Comparative example:

[0069] Aluminum-based composite materials were added to the sediment in the aforementioned sediment remediation device.

[0070] Example:

[0071] Spherical particles, prepared from 6g of aluminum-based composite material, were added to the aforementioned sediment remediation device in a covering manner. The preparation process of the aluminum-based composite material is as follows:

[0072] First, treat the coconut shell activated carbon with dilute hydrochloric acid, then wash the coconut shell activated carbon until the pH of the effluent reaches 5.5, and place it in an oven to dry for later use.

[0073] Secondly, 5g of the above dried coconut shell activated carbon, 1g of aluminum powder and 65g of agate beads were weighed in four stainless steel ball mills (each with a volume of 100mL), i.e. the mass ratio of activated carbon and aluminum powder was 5:1, and the mass ratio of added materials to agate beads was about 1:11; the diameters of the agate beads in each stainless steel ball mill were 6mm, 10mm and 15mm respectively, and the quantity ratio of 6mm, 10mm and 15mm ball milling beads in each stainless steel ball mill was 15:5:1; the diameter of the aluminum powder particles was 80-150μm, and the purity was 99%;

[0074] Thirdly, the four stainless steel ball mills were sealed, vacuumized and then argon was introduced;

[0075] Fourthly, the four stainless steel ball mills were put into a planetary ball mill, the rotation speed of the ball mill was set to 400r / min, and the ball milling time was set to 8h;

[0076] Fifthly, the obtained aluminum-based composite material was taken out after ball milling, mixed with 0.6g of sodium carboxymethyl cellulose (CMC, used as an adhesive) and then put into a granulator to prepare spherical particles, as shown in Figure 2 . Figure 2 The scanning electron microscope image of the spherical particles including partial spherical particles.

[0077] After the addition of the aluminum-based composite material spherical particles was completed, the five sampling ports in the comparative example and the examples were sampled at the 1st day, the 2nd day, the 4th day, the 8th day, the 15th day, the 22nd day, the 29th day and the 36th day respectively. The samples taken from the comparative example were measured for total phosphorus (TP) concentration according to the ammonium molybdate spectrophotometric method, as shown in Figure 4-1 . The samples taken from the examples were measured for total phosphorus (TP) concentration according to the ammonium molybdate spectrophotometric method, as shown in Figure 4-2 . As can be seen from Figure 4-1 and 4-2 , compared with the comparative example, the aluminum-based composite material spherical particles in the examples adsorbed the internal source phosphorus diffusing from the bottom layer, the transition layer and the surface layer towards the lower layer water and the upper layer water in a covering manner, effectively controlled the diffusion of phosphorus in the sediment to the overlying water, thereby reducing the phosphorus concentration in the upper layer water and the lower layer water.

[0078] After the addition of the aluminum-based composite material spherical particles was completed, the five sampling ports in the comparative example and the examples were sampled at the 1st day, the 2nd day, the 9th day, the 16th day, the 23rd day, the 30th day and the 37th day respectively. The samples taken from the comparative example were measured for organic matter content according to the UV 254 spectrophotometric method, as shown in Figure 5-1 . The samples taken from the examples were measured for organic matter content according to the UV 254 spectrophotometric method, as shown in Figure 5-2 . As can be seen fromFigure 5-1 and 5-2 It can be seen that, compared with the comparative example, the aluminum matrix composite spherical particles in the example absorb the light wave numbers of the surface layer, the transition layer and the bottom layer, effectively reducing the light wave numbers of the upper layer water and the lower layer water.

[0079] After the aluminum matrix composite spherical particles are added, the five sampling ports in the comparative example and the example are sampled at the 1st day, the 2nd day, the 4th day, the 9th day, the 16th day, the 23rd day, the 30th day and the 37th day, respectively. The sample taken out in the comparative example is used to determine the concentration of the organic pollutant dichlorophenol (DCP) by liquid chromatography, as shown in Table 1. The sample taken out in the example is used to determine the concentration of the organic pollutant dichlorophenol (DCP) by liquid chromatography, as shown in Table 2. The concentration of dichlorophenol in the upper layer water and the lower layer water is shown in Table 3. Figure 6-1 Figure 6-2 It can be seen that, compared with the comparative example, the aluminum matrix composite spherical particles in the example absorb and decompose the organic pollutant dichlorophenol diffused from the bottom layer, the transition layer and the surface layer towards the lower layer water and the upper layer water in a covering manner, effectively reducing the concentration of dichlorophenol in the upper layer water and the lower layer water. Figure 6-1 6-2 It can be seen that, compared with the comparative example, the aluminum matrix composite spherical particles in the example absorb and decompose the organic pollutant dichlorophenol diffused from the bottom layer, the transition layer and the surface layer towards the lower layer water and the upper layer water in a covering manner, effectively reducing the concentration of dichlorophenol in the upper layer water and the lower layer water.

[0080] The aluminum matrix composite for sediment remediation in the application generates H + The dense oxide film formed after the aluminum powder is exposed to water is dissolved to expose the zero-valent aluminum inside the oxide film; the local alkaline environment formed around the aluminum matrix composite through the galvanic cathodic effect continuously promotes the activation of the zero-valent aluminum in the inner layer of the aluminum powder, and the activated zero-valent aluminum reacts with the endogenous phosphorus released from the sediment to form flocculation and precipitation in the local alkaline environment, thereby continuously fixing the phosphorus released from the sediment; and the activated carbon continuously adsorbs and decomposes the organic matter in the sediment due to its large specific surface area.

[0081] The above examples are the preferred embodiments of the application, but the embodiments of the application are not limited by the above examples, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the application shall be equivalent replacement methods and shall be within the scope of protection of the application.​​

Claims

1. An aluminum-based composite material for sediment remediation, used to cover sediment and immobilize phosphorus and organic matter released from the sediment, characterized in that: The aluminum-based composite material is prepared by ball milling Al powder and acid-treated activated carbon under inert gas conditions. The weight percentage of the acid-treated activated carbon and Al powder is 4~6:

1. The aluminum-based composite material added to the sediment forms a local alkaline environment. The phosphorus released in the sediment is continuously fixed by the continuously dissolved and non-passivated activated zero-valent aluminum. The organic matter in the sediment is adsorbed and decomposed by the activated carbon with a large specific surface area. The aluminum powder, before ball milling, has a particle size of 80–150 μm and a purity of ≥99%. The ball mill speed is 200~400 r / min, and the ball milling time is 4~8 h; The amount of the aluminum-based composite material added to the bottom mud is 1~50g / kg; The activated carbon is activated carbon that has been treated with dilute acid and washed until the pH of the effluent is 5.

5.

2. The aluminum-based composite material for sediment remediation according to claim 1, characterized in that: The activated carbon is selected from one or more of coconut shell activated carbon, wood activated carbon, fruit shell activated carbon, and coal-based activated carbon.

3. The aluminum-based composite material for sediment remediation according to claim 1, characterized in that: The inert gas is selected from one or more of nitrogen, argon, and helium.

4. The aluminum-based composite material for sediment remediation according to claim 1, characterized in that: The aluminum-based composite material was mixed and ball-milled using a planetary ball mill.

5. The aluminum-based composite material for sediment remediation according to claim 4, characterized in that: The ball mill beads in the ball mill have a particle size of 6~20mm.

6. The aluminum-based composite material for sediment remediation according to claim 5, characterized in that: The grinding beads have particle sizes of 6mm, 10mm, and 15mm, and the corresponding grinding bead ratio is 15:5:

1.

7. The aluminum-based composite material for sediment remediation according to claim 6, characterized in that: The grinding beads are made of one or more of the following materials: zirconium oxide, agate, corundum, and stainless steel.

8. The aluminum-based composite material for sediment remediation according to claim 1, characterized in that: The phosphorus released from the sediment includes bound phosphorus, exchangeable phosphorus, occluded phosphorus, authigenic calcium phosphorus, detrital phosphorus, and organic phosphorus. The organic matter released from the sediment includes tetrachloroethylene, dichlorophenol, and p-nitrophenol.

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