Heavy Metal Wastewater Treatment Method and Application

Abstract

This application discloses a method for treating heavy metal wastewater and its applications. In the first aspect of this application, a method for treating heavy metal wastewater is provided. The method for treating heavy metal wastewater includes the following steps: S1: Fix an organic sulfur chelating agent into an anodic aluminum oxide material; S2: Make the anodic aluminum oxide material contact with the heavy metal wastewater for chelation deposition treatment; S3: Conduct a sealing treatment on the anodic aluminum oxide material. During the above treatment process, little or no sludge is generated, largely solving the problems of solid precipitation waste disposal and possible secondary pollution problems existing in the existing heavy metal wastewater treatment process.

Description

Technical Field

[0001] This application relates to the technical field of sewage treatment, and particularly to a method for treating heavy metal wastewater and its application. Background Art

[0002] In the field of heavy metal wastewater treatment, the traditional treatment method is alkaline chemical precipitation. Alkaline substances such as sodium hydroxide, lime, and sodium carbonate are added to the wastewater to form metal hydroxides or salts that are insoluble in water and precipitate for separation. This method has a mature process, simple operation, and stable effect, and can remove most heavy metals when the pH is 8 - 11. However, it also has obvious defects. When the wastewater contains complexing agents, they often form stable metal complexes with heavy metal ions, resulting in poor alkaline precipitation effect. It is necessary to first perform complex-breaking treatment and then carry out alkaline chemical precipitation. On the other hand, when the wastewater contains multiple heavy metal ions, the optimal precipitation pH values of different heavy metal ions will be different. Moreover, after adjusting the alkalinity to precipitate metal ions, it is necessary to add acid to callback the pH value, consuming a large amount of acid and alkali, and at the same time generating a large amount of soluble salts. In addition, the precipitated heavy metal sludge belongs to hazardous solid waste and there is a possibility of secondary pollution.

[0003] Compared with the alkaline chemical precipitation method, adding inorganic sulfides such as Na2S and NaHS to wastewater with a pH of 7 - 9 can form precipitates with lower solubility products with heavy metal ions in the wastewater. It not only has the advantages of less sediment volume and no need to adjust the pH value of the effluent, but also can extract heavy metal ions from some metal complexes. However, sulfides are prone to react with acids to produce toxic hydrogen sulfide gas, and the pH value must be strictly controlled. Moreover, sulfide particles are very small and difficult to settle, and flocculants often need to be added to assist sedimentation. On the other hand, the residual S 2- is also a pollutant and additional removal processes are required.

[0004] For the above two methods, the heavy metal chelation method uses organic sulfides to form insoluble precipitates with multiple heavy metal ions in the wastewater, which can remove multiple heavy metals simultaneously, overcoming the disadvantages of the alkaline chemical precipitation method being greatly affected by complexing agents and being unable to take into account multiple coexisting metal ions. In addition, this method has a wide applicable pH range and can be used under weakly alkaline, neutral, or even acidic conditions. It not only solves the problem of wasting a large amount of acid in the alkaline chemical precipitation method for callback of pH, but also avoids the disadvantage of pollution caused by the volatilization of inorganic sulfides under acidic conditions. However, the sludge precipitate generated by this method still needs special treatment, which not only increases the treatment cost but also has the possibility of secondary pollution. Therefore, it is necessary to provide a method for treating heavy metal wastewater that can solve heavy metal pollution without generating or generating very little sludge. Summary of the Invention

[0005] This application aims to solve at least one of the technical problems existing in the prior art. To this end, this application proposes a heavy metal wastewater treatment method and application.

[0006] In the first aspect of this application, a heavy metal wastewater treatment method is provided. The heavy metal wastewater treatment method includes the following steps:

[0007] S1: Fix an organic sulfur chelating agent into an anodized aluminum oxide material;

[0008] S2: Bring the anodized aluminum oxide material into contact with heavy metal wastewater for chelation deposition treatment;

[0009] S3: Perform a sealing treatment on the anodized aluminum oxide material.

[0010] The heavy metal wastewater treatment method according to the embodiments of this application has at least the following beneficial effects:

[0011] In the above treatment method, first, an organic sulfur chelate is fixed into the pore of anodized aluminum oxide to obtain an anodized aluminum oxide material with the function of capturing heavy metal ions. Subsequently, this anodized aluminum oxide material is brought into contact with heavy metal wastewater, and the heavy metal ions therein are adsorbed into the pore of the anodized aluminum oxide and form precipitates with the organic sulfur chelating agent, thereby enriching the heavy metal ions in the anodized aluminum oxide material. Then, a sealing treatment is performed on it, which can effectively prevent the heavy metal ions deposited in the pores from being released again to harm the environment and does not affect the normal use of the aluminum material after sealing. During the above treatment process, no or very little sludge is generated, which largely solves the problems of solid precipitate waste disposal and possible secondary pollution existing in the prior heavy metal wastewater treatment process.

[0012] Among them, the anodized aluminum oxide material refers to a material containing an alumina pore structure. This pore structure of the material is usually formed by anodization under acidic conditions, such as anodization to form an alumina pore structure under acidic electrolyte conditions such as sulfuric acid, oxalic acid, phosphoric acid, malonic acid, citric acid, malic acid, etc. that make alumina slightly soluble. This pore structure can be either a disordered pore structure or an ordered pore structure, such as a single vertically growing pore, a bifurcated pore, a hierarchical pore, a pore with a specific pore shape, etc. In addition, the anodized aluminum oxide material can be an aluminum material with an alumina pore formed or a material with a composite structure containing it. For the specific shape of the anodized aluminum oxide material, it includes but is not limited to profiles, pipes, plates, foils, membranes, etc.

[0013] In some embodiments of the present application, the method for fixing the organic sulfur chelating agent to the anodic aluminum oxide material in S1 is as follows: The anodic aluminum oxide material is soaked in a solution of the organic sulfur chelating agent, so that the organic sulfur chelating agent is adsorbed into the anodic aluminum oxide material and fixed. By using the soaking and adsorption method and the adsorption effect of the pores of the anodic aluminum oxide, the organic sulfur chelating agent can be conveniently, simply and stably fixed to the anodic aluminum oxide material. It can be understood that other chemical modification methods known in the art can also be used to fix the organic sulfur chelating agent to the anodic aluminum oxide material, but the preparation raw materials and steps are more complex.

[0014] In some embodiments of the present application, the concentration of the organic sulfur chelating agent in the solution is 0.05 - 15 g / L, for example, it can be 0.05 g / L, 0.1 g / L, 0.2 g / L, 0.5 g / L, 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L, 15 g / L, etc. In some of these embodiments, the concentration of the organic sulfur chelating agent in the solution is 0.1 - 15 g / L, 1 - 15 g / L, 5 - 15 g / L.

[0015] In some embodiments of the present application, the temperature for soaking the anodic aluminum oxide material in the solution of the organic sulfur chelating agent is 5 - 35 °C, for example, it can be 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C, etc. In some of these embodiments, the temperature for soaking the anodic aluminum oxide material in the solution of the organic sulfur chelating agent is 10 - 30 °C, 15 - 25 °C.

[0016] In some embodiments of the present application, the soaking time of the anodic aluminum oxide material in the solution of the organic sulfur chelating agent is 5 s - 1 h, for example, it can be 5 s, 10 s, 15 s, 20 s, 30 s, 45 s, 1 min, 2 min, 5 min, 10 min, 15 min, 20 min, 30 min, 45 min, 1 h. In some of these embodiments, the soaking time of the anodic aluminum oxide material in the solution of the organic sulfur chelating agent is 30 s - 1 h, 1 min - 1 h, 30 min - 1 h.

[0017] In some embodiments of the present application, the organic sulfur chelating agent is an anionic water-soluble organic sulfur chelating agent.

[0018] In some embodiments of the present application, the organic sulfur chelating agent is selected from at least one of dithiocarbamate compounds, polythiocarbonate compounds, polythiophosphate compounds, trithiomelamine compounds, xanthate compounds, and thiol compounds.

[0019] In some embodiments of the present application, the dithiocarbamic acid compounds may be substituted or unsubstituted dithiocarbamic acid or dithiocarbamate. Among them, the substitution may be that the hydrogen of the amino group is substituted by groups well-known in the art such as alkyl, hydroxy-substituted alkyl, etc. For example, it may be at least one of dimethyldithiocarbamic acid, diethyldithiocarbamic acid, methylethyldithiocarbamic acid, 4-hydroxybutyldithiocarbamic acid, bis(4-hydroxybutyl)dithiocarbamic acid or its salts, etc.

[0020] In some embodiments of the present application, the dithiocarbamic acid compounds are selected from at least one of dithiocarbamates, dimethyldithiocarbamates, and diethyldithiocarbamates. Specifically, it may be at least one of sodium dithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, potassium dithiocarbamate, potassium dimethyldithiocarbamate, potassium diethyldithiocarbamate, etc.

[0021] In some embodiments of the present application, the polythiocarbonic acid compounds are selected from at least one of dithiocarbonates, trithiocarbonates, tetrathiocarbonates, and pentathiocarbonates. For example, alkali metal salts or alkaline earth metal salts of polythiocarbonic acid. Specifically, it may be at least one of sodium dithiocarbonate, sodium trithiocarbonate, sodium tetrathiocarbonate, sodium pentathiocarbonate, potassium dithiocarbonate, potassium trithiocarbonate, potassium tetrathiocarbonate, potassium pentathiocarbonate, magnesium dithiocarbonate, magnesium trithiocarbonate, magnesium tetrathiocarbonate, magnesium pentathiocarbonate, etc.

[0022] In some embodiments of the present application, the polythiophosphoric acid compounds are selected from at least one of dithiophosphates, trithiophosphates, tetrathiophosphates, and pentathiophosphates. For example, alkali metal salts or alkaline earth metal salts of polythiophosphoric acid. Specifically, it may be at least one of sodium dithiophosphate, sodium trithiophosphate, sodium tetrithiophosphate, sodium pentathiophosphate, potassium dithiophosphate, potassium trithiophosphate, potassium tetrithiophosphate, potassium pentathiophosphate, magnesium dithiophosphate, magnesium trithiophosphate, magnesium tetrithiophosphate, magnesium pentathiophosphate, etc.

[0023] In some embodiments of the present application, the trithiocyanuric acid compounds are selected from alkali metal and / or alkaline earth metal salts of trithiocyanuric acid. More commonly, alkali metal salts of trithiocyanuric acid, such as trisodium trithiocyanuric acid.

[0024] In some embodiments of the present application, the xanthic acid compounds are selected from at least one of xanthates and xanthic acid esters.

[0025] In some embodiments of the present application, the xanthic acid compounds are selected from at least one of ethyl xanthate and polymer-modified xanthic acid esters.

[0026] In some embodiments of the present application, the xanthate compound is selected from at least one of alkali metal ethylxanthate, alkaline earth metal ethylxanthate, and natural polymer modified xanthate esters (such as starch modified xanthate ester, cellulose modified xanthate ester, wood chip modified xanthate ester, etc.).

[0027] In some embodiments of the present application, the thiol compound is selected from at least one of mercaptoacetyl chitosan (MAC), mercaptoacetylated polyacrylamide (MAPAM), mercaptoacetylated hydroxymethylacrylamide (MAMPAM), mercaptoacetylated aminomethyl polyacrylamide (MAAPAM), and mercaptoacetylated sulfomethyl polyacrylamide (MASPAM).

[0028] In some embodiments of the present application, the heavy metal ions in the heavy metal wastewater are ions of at least one element selected from mercury, silver, copper, lead, cadmium, zinc, nickel, and chromium.

[0029] In some embodiments of the present application, the heavy metal ions in the heavy metal wastewater are Hg 2+ 、Ag + 、Cu 2+ 、Pb 2+ 、Cd 2+ 、Zn 2+ 、Ni 2+ 、Cr 6+ 、Cr 3+ and at least one of them.

[0030] In some embodiments of the present application, the treatment time for chelation deposition in S2 is 1 to 30 minutes, for example, 1 minute, 2 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes.

[0031] In some embodiments of the present application, the method for sealing treatment in S3 is to make the anodic aluminum oxide material contact with nickel salt to generate a precipitate filling the film pores for sealing.

[0032] In some embodiments of the present application, the nickel salt is at least one of nickel fluoride and nickel acetate.

[0033] The present application also provides an anodic aluminum oxide material, on which an organic sulfur chelating agent is fixed.

[0034] In some embodiments of the present application, the organic sulfur chelating agent is fixed in the pores of the anodic aluminum oxide material.

[0035] In some embodiments of the present application, the organic sulfur chelating agent is adsorbed in the pores of the anodic aluminum oxide material.

[0036] In the second aspect of the present application, there is provided a sealed anodic aluminum oxide material obtained by the heavy metal wastewater treatment method described above.

[0037] In the third aspect of the present application, there is also provided the application of the sealed anodic aluminum oxide material obtained by the above heavy metal wastewater treatment method in the fields of architectural decoration, photovoltaic solar energy, mechanical equipment, etc.

[0038] In order to overcome the deficiencies of the prior art, the purpose of the present application is to provide a heavy metal wastewater treatment method that can both solve heavy metal pollution and produce little or no sludge. The anodic oxidation film of aluminum and its alloys is an important process for the surface treatment of aluminum materials at present, and has been widely used in the aluminum processing industry for decades. The technology is very mature. The obtained anodic aluminum oxide film has the characteristics of being colorless and transparent, highly porous, and the inner wall of the pore channels being positively charged, and can adsorb a variety of anionic substances. Based on this principle, the present application adsorbs an anionic organic sulfur chelating agent into the pore channels of the anodic oxidation film, and then contacts it with the wastewater containing heavy metal ions, so that the organic sulfur chelating agent reacts with the heavy metal ions adsorbed into the pore channels, and thus deposits into the pore channels. Finally, the anodic oxidation film after capturing heavy metals is sealed by the general sealing process in the aluminum industry, which can effectively prevent the heavy metal ions deposited in the pore channels from being released again to harm the environment, and does not affect the normal use function of the sealed aluminum materials, having double environmental and economic values. Moreover, no sludge or only a very small amount of sludge is produced during the process of this treatment, solving or greatly reducing the problems of the disposal of solid precipitation waste and the possible problem of secondary pollution, and is applicable to anodic oxidation enterprises to treat nickel-sealed wastewater, anodic oxidation enterprises in electroplating industrial areas, or enterprises with both electroplating and anodic oxidation production lines to treat electroplating wastewater containing nickel and other toxic heavy metal ions.

[0039] The additional aspects and advantages of the present application will be partly given in the following description, partly become obvious from the following description, or be understood through the practice of the present application. Description of the Drawings

[0040] Figure 1 is the experimental schematic diagram in the embodiment of the present application.

[0041] Reference numerals: aluminum alloy matrix 100, pore channel array 110, organic sulfur chelating agent 111, heavy metal ion 112, sealing precipitate 120. Detailed Embodiments

[0042] The following will clearly and completely describe the concept of this application and the technical effects generated in combination with the embodiments, so as to fully understand the purpose, features, and effects of this application. Obviously, the described embodiments are only part of the embodiments of this application, rather than all embodiments. Based on the embodiments of this application, other embodiments obtained by those skilled in the art without creative efforts all fall within the scope of protection of this application.

[0043] The embodiments of this application will be described in detail below. The described embodiments are exemplary and are only used to explain this application, and should not be construed as a limitation to this application.

[0044] In the description of this application, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood not to include the number itself, and above, below, within, etc. are understood to include the number itself. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0045] In the description of this application, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0046] The anodization process of the aluminum alloy workpiece involved in the following embodiments specifically includes the following steps:

[0047] Using the aluminum alloy workpiece as the anode and the lead plate as the cathode, treating for 45 minutes under the conditions of 18% sulfuric acid, 21 °C, and 12 V voltage, forming a vertically growing alumina pore array on the surface of the aluminum alloy workpiece, and obtaining an aluminum alloy workpiece with an anodic aluminum oxide film.

[0048] Example 1

[0049] This embodiment provides a method for treating heavy metal wastewater, including the following steps:

[0050] (1) Fixation. Refer to Figure 1, the anodized aluminum alloy workpiece has a pore array 110 of an anodic aluminum oxide film on its aluminum alloy substrate 100. The aluminum alloy workpiece is immersed in an aqueous solution of an organic sulfur chelating agent at room temperature for 60 s. In this embodiment, the aqueous solution of the organic sulfur chelating agent is a 3 g / L aqueous solution of sodium ethylmethyl dithiocarbamate, so that the organic sulfur chelating agent 111 therein is adsorbed into the pore array 110 and fixed. Subsequently, the aluminum alloy workpiece is washed thoroughly with water to remove the organic sulfur chelating agent 111 that remains on the surface of the aluminum alloy workpiece and is not adsorbed.

[0051] (2) Chelating deposition. Refer to Figure 1 , the aluminum alloy workpiece processed in step (1) is placed in a 50 mg / L nickel ion wastewater for 15 min for chelating deposition treatment, so that the heavy metal ions 112 are adsorbed into the pore array 110 and form a chelate with the organic sulfur chelating agent 111 and thus deposit into the pore array 110. The aluminum alloy workpiece is washed thoroughly with water again. Since the diameter of the pores is usually in the nanometer scale, the chelate deposited therein will not be washed out.

[0052] (3) Sealing. Refer to Figure 1 , the aluminum alloy workpiece processed in step (2) is placed in a commercially available nickel fluoride-based normal temperature sealing agent for 15 min to form a sealing precipitate 120 of nickel ions in the pores and deposit it in the pore array 110, thereby sealing the pore array 110, and then the aluminum alloy workpiece is taken out and dried.

[0053] Example 2

[0054] This embodiment provides a method for treating heavy metal wastewater, including the following steps:

[0055] (1) Fixing. The aluminum alloy workpiece is immersed in an aqueous solution of an organic sulfur chelating agent at room temperature for 30 s. In this embodiment, the aqueous solution of the organic sulfur chelating agent is a 2 g / L aqueous solution of tris(mercaptomethyl)triazine trisodium salt, and then the aluminum alloy workpiece is washed thoroughly with water to remove the remaining organic sulfur chelating agent.

[0056] (2) Chelating deposition. The aluminum alloy workpiece processed in step (1) is placed in a 100 mg / L copper ion wastewater for 5 min for chelating deposition treatment, and then the aluminum alloy workpiece is washed thoroughly with water again.

[0057] (3) Sealing. The aluminum alloy workpiece processed in step (2) is placed in a commercially available medium temperature nickel acetate-based sealing agent for 15 min, and then the aluminum alloy workpiece is taken out and dried.

[0058] Example 3

[0059] This embodiment provides a method for treating heavy metal wastewater, including the following steps:

[0060] (1) Fixation. Immerse the aluminum alloy workpiece in an aqueous solution of an organic sulfur chelating agent at room temperature for 60 s. The aqueous solution of the organic sulfur chelating agent in this example is a 1 g / L sodium diethyldithiocarbamate aqueous solution. Subsequently, thoroughly wash the aluminum alloy workpiece with water to remove the residual organic sulfur chelating agent.

[0061] (2) Chelating deposition. Place the aluminum alloy workpiece treated in step (1) into a 10 mg / L mercury ion wastewater for 10 min for chelating deposition treatment, and then thoroughly wash the aluminum alloy workpiece with water again.

[0062] (3) Sealing. Place the aluminum alloy workpiece treated in step (2) into a commercially available high-temperature nickel acetate-based sealing agent for 15 min, and then take out the aluminum alloy workpiece and let it dry.

[0063] Example 4

[0064] This example provides a method for treating heavy metal wastewater, including the following steps:

[0065] (1) Fixation. Immerse the aluminum alloy workpiece in an aqueous solution of an organic sulfur chelating agent at room temperature for 120 s. The aqueous solution of the organic sulfur chelating agent in this example is a 3 g / L sodium dimethyldithiocarbamate aqueous solution. Subsequently, thoroughly wash the aluminum alloy workpiece with water to remove the residual organic sulfur chelating agent.

[0066] (2) Chelating deposition. Place the aluminum alloy workpiece treated in step (1) into a 50 mg / L hexavalent chromium ion wastewater for 15 min for chelating deposition treatment, and then thoroughly wash the aluminum alloy workpiece with water again.

[0067] (3) Sealing. Place the aluminum alloy workpiece treated in step (2) into a commercially available nickel fluoride-based room temperature sealing agent for 15 min, and then take out the aluminum alloy workpiece and let it dry.

[0068] As can be seen from the above examples, the solution provided by this application fixes the organic sulfur chelating agent into the pores of the anodic oxidation film, and then contacts it with the wastewater containing heavy metal ions, so that the heavy metal ions are adsorbed into the pores of the anodic oxidation film and react with the organic sulfur chelating agent, depositing in the pores. Finally, after sealing, it can not only prevent the heavy metal ions deposited in the pores from being released and harming the environment, but also does not affect the normal use function of the aluminum material after sealing, having both environmental and economic values. During the process of this treatment process, no or only a very small amount of sludge is generated, solving or greatly reducing the problem of solid precipitate waste disposal and the possible problem of secondary pollution.

[0069] The present application has been described in detail above in conjunction with the embodiments. However, the present application is not limited to the above embodiments, and various changes can be made without departing from the gist of the present application within the scope of knowledge possessed by those of ordinary skill in the art. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for treating heavy metal wastewater, characterized in that, It includes the following steps: S1: Fix an organic sulfur chelating agent into an anodic aluminum oxide material; S2: Make the anodic aluminum oxide material contact with heavy metal wastewater for chelation deposition treatment; S3: Conduct a sealing treatment on the anodic aluminum oxide material; The method of fixing the organic sulfur chelating agent into the anodic aluminum oxide material in S1 is: soaking the anodic aluminum oxide material in a solution of the organic sulfur chelating agent, so that the organic sulfur chelating agent is adsorbed into the anodic aluminum oxide material and fixed. The organic sulfur chelating agent is an anionic water-soluble organic sulfur chelating agent.

2. The heavy metal wastewater treatment method according to claim 1, characterized in that, In the solution: the concentration of the organic sulfur chelating agent is 0.05 - 15 g / L, and / or the temperature of the soaking treatment is 5 - 35 °C, and / or the time of the soaking treatment is 5 s - 1 h.

3. The heavy metal wastewater treatment method according to claim 1, wherein The organic sulfur chelating agent is selected from at least one of dithiocarbamic acid compounds, polythiocarbonic acid compounds, polythiophosphoric acid compounds, trithiocyanuric acid compounds, xanthic acid compounds, and thiol compounds.

4. The heavy metal wastewater treatment method according to claim 3, characterized in that The dithiocarbamic acid compounds are selected from at least one of dithiocarbamates, dimethyldithiocarbamates, diethyldithiocarbamates, and methylethyldithiocarbamates. The polythiocarbonic acid compounds are selected from at least one of dithiocarbonates, trithiocarbonates, tetrathiocarbonates, and pentathiocarbonates. The polythiophosphoric acid compounds are selected from at least one of dithiophosphates, trithiophosphates, tetrathiophosphates, and pentathiophosphates. The trithiocyanuric acid compounds are selected from tris(mercapto)triazine trisodium. The xanthic acid compounds are selected from at least one of xanthates and xanthic acid esters. The thiol compounds are selected from at least one of mercaptoacetylchitosan, mercaptoacetylated polyacrylamide, mercaptoacetylated hydroxymethylacrylamide, mercaptoacetylated aminomethyl polyacrylamide, and mercaptoacetylated sulfomethyl polyacrylamide.

5. The heavy metal wastewater treatment method according to any one of claims 1 to 4, characterized in that, The heavy metal ions in the heavy metal wastewater are ions of at least one element among mercury, silver, copper, lead, cadmium, zinc, nickel, and chromium, and / or the treatment time of the chelation deposition is 1 - 30 min.

6. The heavy metal wastewater treatment method according to claim 1, characterized in that, The method of the sealing treatment in S3 is to make the anodic aluminum oxide material contact with a nickel salt to generate a precipitate filling the film pores for sealing.

7. The heavy metal wastewater treatment method according to claim 6, wherein, The nickel salt is at least one of nickel fluoride and nickel acetate.

8. The sealed anodic aluminum oxide material obtained by the heavy metal wastewater treatment method according to any one of claims 1 to 7.

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