Desulfurization wastewater heavy metal ion adsorbent, preparation method therefor, and use thereof

Abstract

A desulfurization wastewater heavy metal ion adsorbent, a preparation method therefor, and a use thereof. The preparation method for said adsorbent comprises the following steps: (1) uniformly mixing gluconic acid, sodium dihydrogen phosphate, and an aminoglycoside antibiotic to prepare a mixed solution; (2) adding β-cyclodextrin into the mixed solution, and stirring until the solution becomes viscous to prepare a viscous mixture; and (3) heating, baking, washing, and drying the viscous mixture to prepare said adsorbent. According to said adsorbent, hydroxyl groups are linked to carboxyl groups by means of an esterification reaction, and then amino groups are linked by means of an amidation reaction, forming an effect of the synergy of the three functional groups in promoting the adsorption of heavy metal ions. Said adsorbent has a fast adsorption rate, is capable of rapidly separating heavy metal ion pollutants from water, and has a high adsorption capacity for heavy metal ions.

Description

A desulfurization wastewater heavy metal ion adsorbent and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of power plant wastewater treatment, in particular to a desulfurization wastewater heavy metal ion adsorbent and a preparation method and application thereof. Background Art

[0002] Coal-fired power plants inevitably generate various types of wastewater during power generation. For example, desulfurization wastewater often contains heavy metal ion pollutants such as lead, chromium, cadmium, copper, zinc, manganese, and mercury. Currently, national environmental protection standards for coal-fired power plant wastewater discharge are becoming increasingly stringent. Meeting these standards requires significant energy and material resources to maintain equipment operation, impacting the economic profitability of the power plants themselves. Therefore, the cost-effective treatment of power plant wastewater is of great significance.

[0003] Current methods for treating heavy metal-contaminated water include physical enrichment and precipitation, ion exchange, electrochemical methods, adsorption, and bioremediation. Adsorption, which utilizes porous adsorbents to absorb one or more pollutants from wastewater, recovers or removes them, thereby purifying the wastewater. Adsorption has attracted significant attention due to its ease of operation, recyclability, and minimal pollution. However, adsorption methods are generally subject to issues such as high operating costs, slow adsorption rates, and limited effectiveness.

[0004] In view of this, the present invention is proposed.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to provide a desulfurization wastewater heavy metal ion adsorbent and its preparation method and application. The desulfurization wastewater heavy metal ion adsorbent has a fast adsorption speed, can quickly separate heavy metal ion pollutants from water, and has a high adsorption rate for heavy metal ions.

[0007] The present invention provides a method for preparing a heavy metal ion adsorbent for desulfurization wastewater, comprising the following steps:

[0008] S1: mixing gluconic acid, sodium dihydrogen phosphate and aminoglycoside antibiotics to prepare a mixed solution;

[0009] S2: adding β-cyclodextrin to the mixed solution and stirring until it becomes viscous to obtain a mixed viscous substance;

[0010] S3: heating, baking, washing and drying the mixed viscous material to obtain a desulfurization wastewater heavy metal ion adsorbent.

[0011] Specifically, in step S1, the mass content of gluconic acid in the mixed solution is 2-50%, preferably 20-40%; the mass content of sodium dihydrogen phosphate in the mixed solution is 1-5%, preferably 1-3%; the mass content of aminoglycoside antibiotics in the mixed solution is 1-20%, preferably 10-15%; that is, the mass ratio of gluconic acid, sodium dihydrogen phosphate, and aminoglycoside antibiotics is (2-50): (1-5): (1-20), preferably (20-40): (1-3): (10-15). In addition, the mixture is mixed under stirring at a speed of 150-250 r / min and a stirring time of 5-15 minutes.

[0012] In step S2, the mass ratio of gluconic acid to β-cyclodextrin is (2-50):(120-180), preferably (20-40):(120-150).

[0013] In step S3, the heating temperature is 70-90°C and the heating time is 5-7h. The heating process promotes the esterification reaction between the hydroxyl group of β-cyclodextrin and the carboxyl group of gluconic acid; the baking temperature is 170-190°C and the baking time is 8-12min. The baking process ensures that the amidation reaction between the ester group and the amino group proceeds smoothly; washing can be done with deionized water; the drying temperature can be 30-50°C and the drying time is 10-15h.

[0014] Gluconic acid, derived from the oxidation of glucose, is a cheap, readily available, renewable resource rich in carboxyl groups that can chelate metal ions. Gentamicin, a broad-spectrum aminoglycoside antibiotic produced by microorganisms, exhibits excellent thermal stability and is a renewable resource rich in amino groups that can coordinate and chelate metal ions. β-cyclodextrin, rich in hydroxyl groups, has excellent adsorption and encapsulation properties for many organic molecules and inorganic heavy metals. It is a safe, non-toxic, biodegradable, and highly reusable raw material.

[0015] The materials used in the present invention are all natural biological products, which are low-priced and renewable, and can adsorb major pollutants in water bodies. In particular, the above-mentioned preparation method connects hydroxyl and carboxyl groups through an esterification reaction, and then connects amino groups through an amidation reaction, forming a three-functional group linkage to promote the adsorption of heavy metal ions. The adsorption speed is fast, and heavy metal ion pollutants can be quickly separated from water bodies. It is suitable for high and low concentration heavy metal ion wastewater.

[0016] The present invention also provides a desulfurization wastewater heavy metal ion adsorbent, which is prepared according to the above preparation method.

[0017] The present invention also provides the use of the above-mentioned desulfurization wastewater heavy metal ion adsorbent in removing heavy metals in desulfurization wastewater.

[0018] Specifically, the dosage of heavy metal ion adsorbent for desulfurization wastewater is 1-3 g / L. In addition, the adsorbent that adsorbs heavy metal ions and other pollutants can be desorbed and regenerated using dilute acid (e.g., 0.01-0.1 mol / L dilute sulfuric acid), or directly calcined at above 300°C to recover heavy metal ions.

[0019] The present invention uses gluconic acid, sodium dihydrogen phosphate, aminoglycoside antibiotics, and beta-cyclodextrin as raw materials. The main functional materials are all natural renewable products, easily biodegradable, environmentally friendly and easy to handle. The main functional groups are hydroxyl, carboxyl and amino groups. The hydroxyl and carboxyl groups are connected by esterification reaction, and then the amino groups are connected by amidation reaction, forming a three-functional group linkage to promote the adsorption of heavy metal ions. The adsorption speed is fast, and heavy metal ion pollutants can be quickly separated from the water body. It is suitable for various types of acidic and alkaline pH value wastewater, and realizes broad-spectrum adsorption to remove various heavy metal ions in desulfurization wastewater. The whole process is green and environmentally friendly, and there is no secondary pollution in adsorbent adsorption and post-treatment. The purification mode cost is extremely low and the application is not limited by scenarios. DETAILED DESCRIPTION

[0020] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular also includes the plural. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] Example 1

[0024] The desulfurization wastewater heavy metal ion adsorbent of this embodiment is mainly made of gluconic acid, sodium dihydrogen phosphate, gentamicin and β-cyclodextrin, and the mass ratio of gluconic acid, sodium dihydrogen phosphate, gentamicin and β-cyclodextrin is 20:1:10:120.

[0025] The preparation method of the desulfurization wastewater heavy metal ion adsorbent of this embodiment comprises the following steps:

[0026] A gluconic acid solution with a mass content of 20% was first prepared, and then sodium dihydrogen phosphate and gentamicin were added to the gluconic acid solution, and stirred at 200 r / min for 10 minutes to fully dissolve to prepare a mixed solution; wherein the mass content of sodium dihydrogen phosphate in the mixed solution was 1wt%, and the mass content of gentamicin was 10wt%.

[0027] β-cyclodextrin was added to the mixed solution, with a mass ratio of gluconic acid to β-cyclodextrin of 20:120. After stirring for about 15 minutes until viscous, the mixture was heated at 80°C for 6 hours to promote the esterification reaction between the hydroxyl groups of β-cyclodextrin and the carboxyl groups of gluconic acid. The mixture was then baked at 180°C for 10 minutes to ensure smooth amidation reaction between the ester groups and the amino groups. The resulting mixture was washed three times with deionized water and then baked at 40°C for 12 hours to obtain a desulfurization wastewater heavy metal ion adsorbent.

[0028] The above-mentioned desulfurization wastewater heavy metal ion adsorbent was added into the desulfurization wastewater to be treated at 2 g / L and stirred for 30 minutes. The water quality of the desulfurization wastewater before and after treatment was tested. The results are shown in Table 1.

[0029] Table 1 Water quality test results of desulfurization wastewater before and after treatment

[0030] Example 2

[0031] The desulfurization wastewater heavy metal ion adsorbent of this embodiment is mainly made of gluconic acid, sodium dihydrogen phosphate, gentamicin and β-cyclodextrin, and the mass ratio of gluconic acid, sodium dihydrogen phosphate, gentamicin and β-cyclodextrin is 30:2:12:130.

[0032] The preparation method of the desulfurization wastewater heavy metal ion adsorbent of this embodiment comprises the following steps:

[0033] A gluconic acid solution with a mass content of 30% was first prepared, and then sodium dihydrogen phosphate and gentamicin were added to the gluconic acid solution, and stirred at 150 r / min for 15 minutes to fully dissolve, thereby preparing a mixed solution; wherein the mass content of sodium dihydrogen phosphate in the mixed solution was 2wt%, and the mass content of gentamicin was 12wt%.

[0034] β-cyclodextrin was added to the mixed solution, with a mass ratio of gluconic acid to β-cyclodextrin of 30:130. After stirring for about 15 minutes until viscous, the mixture was heated at 70°C for 7 hours to promote the esterification reaction between the hydroxyl groups of β-cyclodextrin and the carboxyl groups of gluconic acid. The mixture was then baked at 170°C for 12 minutes to ensure smooth amidation reaction between the ester groups and the amino groups. The resulting mixture was washed three times with deionized water and then baked at 30°C for 15 hours to obtain a heavy metal ion adsorbent for desulfurization wastewater.

[0035] The above-mentioned desulfurization wastewater heavy metal ion adsorbent was added into the desulfurization wastewater to be treated at 2 g / L and stirred for 30 minutes. The water quality of the desulfurization wastewater before and after treatment was tested. The results are shown in Table 2.

[0036] Table 2 Water quality test results of desulfurization wastewater before and after treatment

[0037] Example 3

[0038] The desulfurization wastewater heavy metal ion adsorbent of this embodiment is mainly made of gluconic acid, sodium dihydrogen phosphate, gentamicin and β-cyclodextrin, and the mass ratio of gluconic acid, sodium dihydrogen phosphate, gentamicin and β-cyclodextrin is 40:3:15:150.

[0039] The preparation method of the desulfurization wastewater heavy metal ion adsorbent of this embodiment comprises the following steps:

[0040] A gluconic acid solution with a mass content of 40% was first prepared, and then sodium dihydrogen phosphate and gentamicin were added to the gluconic acid solution, and stirred at 250 r / min for 5 minutes to fully dissolve, thereby preparing a mixed solution; wherein the mass content of sodium dihydrogen phosphate in the mixed solution was 3wt%, and the mass content of gentamicin was 15wt%.

[0041] β-cyclodextrin was added to the mixed solution, with a mass ratio of gluconic acid to β-cyclodextrin of 40:150. After stirring for about 15 minutes until viscous, the mixture was heated at 90°C for 5 hours to promote the esterification reaction between the hydroxyl groups of β-cyclodextrin and the carboxyl groups of gluconic acid. The mixture was then baked at 190°C for 8 minutes to ensure smooth amidation reaction between the ester group and the amino group. The resulting mixture was washed three times with deionized water and then baked at 50°C for 10 hours to obtain a desulfurization wastewater heavy metal ion adsorbent.

[0042] The above-mentioned desulfurization wastewater heavy metal ion adsorbent was added into the desulfurization wastewater to be treated at 2 g / L and stirred for 30 minutes. The water quality of the desulfurization wastewater before and after treatment was tested. The results are shown in Table 3.

[0043] Table 3 Water quality test results of desulfurization wastewater before and after treatment

[0044] Comparative Example 1

[0045] The desulfurization wastewater heavy metal ion adsorbent of this comparative example is mainly made of β-cyclodextrin.

[0046] The preparation method of the desulfurization wastewater heavy metal ion adsorbent of this comparative example comprises the following steps:

[0047] Add β-cyclodextrin to water, stir until viscous for about 15 minutes, heat at 80°C for 6 hours, and then bake at 180°C for 10 minutes. After washing three times with deionized water, heat and bake at 40°C for 12 hours to obtain a desulfurization wastewater heavy metal ion adsorbent.

[0048] The above-mentioned desulfurization wastewater heavy metal ion adsorbent was added into the desulfurization wastewater to be treated at 2 g / L and stirred for 30 minutes. The water quality of the desulfurization wastewater before and after treatment was tested. The results are shown in Table 4.

[0049] Table 4 Water quality test results of desulfurization wastewater before and after treatment

[0050] Comparative Example 2

[0051] The desulfurization wastewater heavy metal ion adsorbent of this comparative example is mainly made of gluconic acid and β-cyclodextrin (ie, no sodium dihydrogen phosphate and gentamicin are added), and the mass ratio between gluconic acid and β-cyclodextrin is 20:120.

[0052] The preparation method of the desulfurization wastewater heavy metal ion adsorbent of this comparative example comprises the following steps:

[0053] First, a 20% gluconic acid solution was prepared, followed by the addition of β-cyclodextrin in a 20:120 ratio. After stirring for approximately 15 minutes until a viscous solution was formed, the mixture was heated at 80°C for 6 hours and then baked at 180°C for 10 minutes. The resulting mixture was washed three times with deionized water and then baked at 40°C for 12 hours to produce a desulfurization wastewater heavy metal ion adsorbent.

[0054] The above-mentioned desulfurization wastewater heavy metal ion adsorbent was added into the desulfurization wastewater to be treated at 2 g / L and stirred for 30 minutes. The water quality of the desulfurization wastewater before and after treatment was tested. The results are shown in Table 5.

[0055] Table 5 Water quality test results of desulfurization wastewater before and after treatment

[0056] Comparative Example 3

[0057] The desulfurization wastewater heavy metal ion adsorbent of this comparative example is mainly made of gluconic acid, gentamicin and β-cyclodextrin (ie, no sodium dihydrogen phosphate is added), and the mass ratio of gluconic acid, gentamicin and β-cyclodextrin is 20:10:120.

[0058] The preparation method of the desulfurization wastewater heavy metal ion adsorbent of this comparative example comprises the following steps:

[0059] First, a gluconic acid solution with a mass content of 20% was prepared, and then gentamicin was added to the gluconic acid solution and stirred at 200 r / min for 10 minutes to fully dissolve the mixture, thereby preparing a mixed solution; wherein the mass content of gentamicin was 10 wt%.

[0060] β-cyclodextrin was added to the mixed solution, with a mass ratio of gluconic acid to β-cyclodextrin of 20:120. After stirring for about 15 minutes until viscous, the mixture was heated at 80°C for 6 hours to promote the esterification reaction between the hydroxyl groups of β-cyclodextrin and the carboxyl groups of gluconic acid. The mixture was then baked at 180°C for 10 minutes to ensure smooth amidation reaction between the ester groups and the amino groups. The resulting mixture was washed three times with deionized water and then baked at 40°C for 12 hours to obtain a desulfurization wastewater heavy metal ion adsorbent.

[0061] The above-mentioned desulfurization wastewater heavy metal ion adsorbent was added into the desulfurization wastewater to be treated at 2 g / L and stirred for 30 minutes. The water quality of the desulfurization wastewater before and after treatment was tested. The results are shown in Table 6.

[0062] Table 6 Water quality test results of desulfurization wastewater before and after treatment

[0063] Comparative Example 4

[0064] The desulfurization wastewater heavy metal ion adsorbent of this comparative example is mainly made of gluconic acid, sodium dihydrogen phosphate and β-cyclodextrin (ie, no gentamicin is added), and the mass ratio of gluconic acid, sodium dihydrogen phosphate and β-cyclodextrin is 20:1:120.

[0065] The preparation method of the desulfurization wastewater heavy metal ion adsorbent of this comparative example comprises the following steps:

[0066] First, a gluconic acid solution with a mass content of 20% was prepared, and then sodium dihydrogen phosphate was added to the gluconic acid solution, and stirred at 200 r / min for 10 minutes to fully dissolve, thereby preparing a mixed solution; wherein the mass content of sodium dihydrogen phosphate in the mixed solution was 1wt%.

[0067] β-cyclodextrin was added to the mixed solution, with a mass ratio of gluconic acid to β-cyclodextrin of 20:120. After stirring for about 15 minutes until viscous, the mixture was heated at 80°C for 6 hours to promote the esterification reaction between the hydroxyl groups of β-cyclodextrin and the carboxyl groups of gluconic acid. The mixture was then baked at 180°C for 10 minutes to ensure smooth amidation reaction between the ester groups and the amino groups. The resulting mixture was washed three times with deionized water and then baked at 40°C for 12 hours to obtain a desulfurization wastewater heavy metal ion adsorbent.

[0068] The above-mentioned desulfurization wastewater heavy metal ion adsorbent was added into the desulfurization wastewater to be treated at 2 g / L and stirred for 30 minutes. The water quality of the desulfurization wastewater before and after treatment was tested. The results are shown in Table 7.

[0069] Table 7 Water quality test results of desulfurization wastewater before and after treatment

[0070] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a heavy metal ion adsorbent for desulfurization wastewater, characterized in that: The steps include: S1: mixing gluconic acid, sodium dihydrogen phosphate and aminoglycoside antibiotics to prepare a mixed solution; S2: adding β-cyclodextrin to the mixed solution and stirring until it becomes viscous to obtain a mixed viscous substance; S3: heating, baking, washing and drying the mixed viscous material to obtain a desulfurization wastewater heavy metal ion adsorbent.

2. The preparation method according to claim 1, characterized in that The mass content of gluconic acid in the mixed solution is 2-50%, preferably 20-40%.

3. The preparation method according to claim 1, characterized in that The mass content of sodium dihydrogen phosphate in the mixed solution is 1-5%, preferably 1-3%.

4. The preparation method according to claim 1, characterized in that The mass content of the aminoglycoside antibiotic in the mixed solution is 1-20%, preferably 10-15%; preferably, the aminoglycoside antibiotic is gentamicin.

5. The preparation method according to claim 1, characterized in that The mass ratio of gluconic acid to beta-cyclodextrin is (2-50):(120-180), preferably (20-40):(120-150).

6. The preparation method according to claim 1, characterized in that The heating temperature is 70-90°C and the heating time is 5-7h.

7. The preparation method according to claim 1, characterized in that The baking temperature is 170-190°C and the baking time is 8-12 minutes.

8. A desulfurization wastewater heavy metal ion adsorbent, characterized in that: Prepared according to the preparation method according to any one of claims 1-7.

9. Use of the desulfurization wastewater heavy metal ion adsorbent according to claim 8 in removing heavy metals from desulfurization wastewater.

10. The use according to claim 9, characterized in that The dosage of heavy metal ion adsorbent for desulfurization wastewater is 1-3g / L.

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