Preparation method of red mud-based arm / niooh adsorption material for dye wastewater adsorption

Abstract

The application discloses a preparation method of a red mud-based ARM / NiOOH adsorbing material for dye wastewater adsorption, and specifically discloses the following steps: ①activating red mud (RM); and ②preparing an ARM / NiOOH composite material.The red mud raw material is abundant in source, and the nickel-based material is abundant in substance, low in price, non-toxic and harmless, and most importantly, has good adsorbing performance, so that the red mud is often used as an adsorbing material.

Description

Technical Field

[0001] This invention relates to the adsorption of organic pollutants in wastewater, specifically to a method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater. Background Technology

[0002] Red mud, also known as bauxite residue, is an industrial solid waste generated after bauxite refining. Currently, red mud is mostly stored in open-air dams, and my country's red mud stockpiles have reached as high as 500 million tons, causing environmental pollution. Therefore, from the perspectives of environmental protection and sustainable resource utilization, it is necessary to comprehensively utilize red mud to achieve its harmlessness, reduction, and resource recovery.

[0003] Red mud, as a byproduct of alumina production, has a large specific surface area and contains a large amount of active oxides such as CaO, Al2O3 and Fe2O3. It has been proven to have good adsorption performance for anions such as Congo red.

[0004] However, red mud itself has limited adsorption capacity. Appropriate modification of red mud before use as an adsorbent can greatly improve its adsorption effect. NiOOH, as a nanomaterial, is suitable for use as an adsorbent in the treatment of dye wastewater due to its stable physical and chemical properties, low toxicity, easy availability, low cost, large specific surface area, and high activity.

[0005] This invention prepares a composite adsorbent by loading NiOOH onto modified red mud, thereby improving the adsorption activity of NiOOH and achieving the goal of "treating waste with waste". This provides a new approach for the resource utilization of red mud and the rational treatment of dye wastewater. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater. The ARM / NiOOH composite adsorbent is prepared by a hydrothermal method to improve the adsorption activity of NiOOH and achieve the goal of "treating waste with waste".

[0007] This invention is achieved through the following technical solution:

[0008] (1) Activation of red mud (RM):

[0009] Step 1: Drying, grinding, and sieving the red mud;

[0010] Step 2: Mix the above-mentioned red mud with a certain amount of H2SO4. After mixing, centrifuge, dry, grind and sieve to obtain activated red mud (ARM).

[0011] (2) Preparation of ARM / NiOOH composite material:

[0012] Step 1: Take a certain amount of NiCl2·6H2O, add it to deionized water, and stir to dissolve;

[0013] Step 2: Add a certain amount of activated red mud to the above solution and stir to make it homogenized;

[0014] Step 3: While stirring, add a certain amount of NaOH solution;

[0015] Step 4: Transfer the above solution into a polytetrafluoroethylene liner for hydrothermal treatment;

[0016] Step 5: Wash the hydrothermal products with deionized water and anhydrous ethanol, centrifuge, and dry the precipitate to obtain the ARM / NiOOH adsorbent material;

[0017] Furthermore, in step (1), the red mud drying temperature is 60 ℃, the drying time is 12 h, the grinding time is 30 min, and the sieve is 200 mesh.

[0018] Furthermore, in step two of step (1), the amount of red mud and H2SO4 added is based on a solid-liquid ratio of 1:5 (g:mL), and the concentration of H2SO4 is 5 mol / L. -1 After stirring, the product was washed three times each with deionized water and anhydrous ethanol. The centrifuged product was then dried in a 60 °C oven for 12 h. After drying, the product was ground for 30 min to obtain activated red mud (ARM).

[0019] Furthermore, in step (2), the amount of NiCl2·6H2O in step one is 0.5-1 mol, which is dissolved in 40 mL of deionized water and stirred for 30 min.

[0020] Furthermore, in step (2) of the above-mentioned step, the amount of activated red mud added is 2 g, and the stirring time is 30 min.

[0021] Furthermore, in step three of step (2), 40 mL of 0.5 mol L... -1 NaOH solution.

[0022] Furthermore, in step four of step (2), the hydrothermal temperature is 180 ℃ and the temperature is maintained for 12 h.

[0023] Furthermore, in step (2), the material is washed three times each with deionized water and anhydrous ethanol, and then dried at 60 °C for 12 h to obtain the ARM / NiOOH adsorbent material.

[0024] Furthermore, the ARM / NiOOH composite adsorbent was applied to adsorb Congo red dye from wastewater.

[0025] Compared with the prior art, the present invention has the following superior effects:

[0026] Red mud, as a byproduct of alumina production, has a large specific surface area and contains a large amount of active oxides such as CaO, Al2O3 and Fe2O3. It has been proven to have good adsorption performance for anions such as Congo red.

[0027] However, red mud itself has limited adsorption capacity. Appropriate modification of red mud before use as an adsorbent can greatly improve its adsorption effect. NiOOH, as a nanomaterial, is suitable for use as an adsorbent in the treatment of dye wastewater due to its stable physical and chemical properties, low toxicity, easy availability, low cost, large specific surface area, and high activity.

[0028] This invention prepares a composite adsorbent by loading NiOOH onto modified red mud, thereby improving the adsorption activity of NiOOH and achieving the goal of "treating waste with waste". This provides a new approach for the resource utilization of red mud and the rational treatment of dye wastewater. Attached Figure Description

[0029] Figure 1 The images show a comparison of the XRD patterns of the ARM / NiOOH adsorbent materials obtained in Examples 1, 2, and 3 of this invention with the original red mud.

[0030] Figure 2 This is a SEM image of the ARM / NiOOH adsorbent material obtained in Example 2 of the present invention;

[0031] Figure 3 This is an adsorption diagram showing the maximum adsorption capacity of Congo Red by the ARM / NiOOH adsorbent material obtained in Example 2 of this invention. Implementation

[0032] To enhance understanding of the present invention, the present invention will be further described below with reference to specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be used to limit the scope of protection of the present invention.

[0033] This invention relates to a method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater, comprising the following steps:

[0034] (1) Activation of red mud (RM):

[0035] Step 1: Dry the red mud in a 60 ℃ oven for 12 h, grind the dried sample for 30 min, and sieve through a 200 mesh sieve; Step 2: Mix the above red mud with 5 mol L -1H2SO4 was mixed and stirred at a solid-liquid ratio of 1:5 (g:mL). After stirring, the mixture was washed three times each with deionized water and anhydrous ethanol during centrifugation. The precipitate after centrifugation was dried in an oven at 60 ℃ for 12 h. After drying, it was ground for 30 min and sieved through a 200-mesh sieve to obtain activated red mud (ARM).

[0036] (2) Preparation of ARM / NiOOH composite material:

[0037] Step 1: Add 0.5-1 mol NiCl2·6H2O to 40 mL of deionized water and stir for 30 min; Step 2: Add 2 g of activated red mud to the above solution and stir for 30 min; Step 3: While stirring, add 40 mL of 0.5 mol / L NiCl2·6H2O. -1 Step 4: Add the above liquid to the polytetrafluoroethylene liner for hydrothermal treatment at a temperature of 180℃ for 24 h; Step 5: Wash the hydrothermal product three times each with deionized water and anhydrous ethanol, and dry the precipitate after centrifugation in a 60℃ oven for 12 h. After drying, grind for 30 min to obtain ARM / NiOOH adsorbent material.

[0038] Take 0.02 g of ARM / NiOOH adsorbent material and put it into 80 mL of 100 mg / L Congo red solution. Stir magnetically in the dark for 2 h. Take samples every 10 min in the first h and every 30 min in the second h. Use a UV-Vis spectrophotometer to test its adsorption.

[0039] Implementation Case 1:

[0040] (1) Activation of red mud (RM):

[0041] Step 1: Dry the red mud in a 60 ℃ oven for 12 h, grind the dried sample for 30 min, and sieve through a 200 mesh sieve; Step 2: Mix the above red mud with 5 mol L -1 H2SO4 was mixed and stirred at a solid-liquid ratio of 1:5 (g:mL). After stirring, the mixture was washed three times each with deionized water and anhydrous ethanol during centrifugation. The precipitate after centrifugation was dried in an oven at 60 ℃ for 12 h. After drying, it was ground for 30 min and sieved through a 200-mesh sieve to obtain activated red mud (ARM).

[0042] (2) Preparation of ARM / NiOOH composite material:

[0043] Step 1: Add 0.5 mol NiCl2·6H2O to 40 mL of deionized water and stir for 30 min; Step 2: Add 2 g of activated red mud to the above solution and stir for 30 min; Step 3: While stirring, add 40 mL of 0.5 mol L... -1 Step 4: Add the above liquid to the polytetrafluoroethylene liner for hydrothermal treatment at a temperature of 180 °C for 24 h; Step 5: Wash the hydrothermal product three times each with deionized water and anhydrous ethanol, and dry the precipitate after centrifugation in a 60 °C oven for 12 h. After drying, grind for 30 min to obtain ARM / NiOOH-0.5 adsorbent material;

[0044] Take 0.02g of ARM / NiOOH-0.5 adsorbent material and put it into 80mL of 100mg / L Congo red solution. Stir magnetically in the dark for 2 hours. Take samples every 10 minutes in the first hour and every 30 minutes in the second hour. Use a UV-Vis spectrophotometer to test its adsorption.

[0045] Implementation Case 2:

[0046] (1) Activation of red mud (RM):

[0047] Step 1: Dry the red mud in a 60 ℃ oven for 12 h, grind the dried sample for 30 min, and sieve through a 200 mesh sieve; Step 2: Mix the above red mud with 5 mol L -1 H2SO4 was mixed and stirred at a solid-liquid ratio of 1:5 (g:mL). After stirring, the mixture was washed three times each with deionized water and anhydrous ethanol during centrifugation. The precipitate after centrifugation was dried in an oven at 60 ℃ for 12 h. After drying, it was ground for 30 min and sieved through a 200-mesh sieve to obtain activated red mud (ARM).

[0048] (2) Preparation of ARM / NiOOH composite material:

[0049] Step 1: Add 0.75 mol NiCl2·6H2O to 40 mL of deionized water and stir for 30 min; Step 2: Add 2 g of activated red mud to the above solution and stir for 30 min; Step 3: While stirring, add 40 mL of 0.5 mol L... -1Step 4: Add the above liquid to the polytetrafluoroethylene liner for hydrothermal treatment at a temperature of 180 °C for 24 h; Step 5: Wash the hydrothermal product three times each with deionized water and anhydrous ethanol, and dry the precipitate after centrifugation in a 60 °C oven for 12 h. After drying, grind for 30 min to obtain ARM / NiOOH-0.75 adsorbent material;

[0050] Take 0.02g of ARM / NiOOH-0.75 adsorbent material and put it into 80mL of 100mg / L Congo red solution. Stir magnetically in the dark for 2 hours. Take samples every 10 minutes in the first hour and every 30 minutes in the second hour. Use a UV-Vis spectrophotometer to test its adsorption.

[0051] Implementation Case 3:

[0052] (1) Activation of red mud (RM):

[0053] Step 1: Dry the red mud in a 60 ℃ oven for 12 h, grind the dried sample for 30 min, and sieve through a 200 mesh sieve; Step 2: Mix the above red mud with 5 mol L -1 H2SO4 was mixed and stirred at a solid-liquid ratio of 1:5 (g:mL). After stirring, the mixture was washed three times each with deionized water and anhydrous ethanol during centrifugation. The precipitate after centrifugation was dried in an oven at 60 ℃ for 12 h. After drying, it was ground for 30 min and sieved through a 200-mesh sieve to obtain activated red mud (ARM).

[0054] (2) Preparation of ARM / NiOOH composite material:

[0055] Step 1: Add 1.0 mol NiCl2·6H2O to 40 mL of deionized water and stir for 30 min; Step 2: Add 2 g of activated red mud to the above solution and stir for 30 min; Step 3: While stirring, add 40 mL of 0.5 mol L... -1 Step 4: Add the above liquid to the polytetrafluoroethylene liner for hydrothermal treatment at a temperature of 180 °C for 24 h; Step 5: Wash the hydrothermal product three times each with deionized water and anhydrous ethanol, and dry the precipitate after centrifugation in a 60 °C oven for 12 h. After drying, grind for 30 min to obtain ARM / NiOOH-1 adsorbent material.

[0056] Take 0.02g of ARM / NiOOH-1 adsorbent material and put it into 80mL of 100mg / L Congo red solution. Stir magnetically in the dark for 2 hours. Take samples every 10 minutes in the first hour and every 30 minutes in the second hour. Use a UV-Vis spectrophotometer to test its adsorption.

Claims

1. A method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater, characterized in that, Includes the following steps: (1) Activation of red mud (RM): Step 1: Drying, grinding, and sieving the red mud; Step 2: Mix the above-mentioned red mud with a certain amount of H2SO4. After mixing, centrifuge, dry, grind and sieve to obtain activated red mud (ARM). (2) Preparation of ARM / NiOOH composite material: Step 1: Take a certain amount of NiCl2·6H2O, add it to deionized water, and stir to dissolve; Step 2: Add a certain amount of activated red mud to the above solution and stir to make it homogenized; Step 3: While stirring, add a certain amount of NaOH solution; Step 4: Transfer the above solution into a polytetrafluoroethylene liner for hydrothermal treatment; Step 5: Wash the hydrothermal products with deionized water and anhydrous ethanol, centrifuge, and dry the precipitate to obtain the ARM / NiOOH adsorbent material.

2. The preparation method of a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater according to claim 1, characterized in that, In step (1), the red mud is dried at a temperature of 60 ℃ for 12 h, ground for 30 min, and sieved through a 200 mesh sieve.

3. The method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater according to claim 1, characterized in that, In step (1), the amount of red mud and H2SO4 added in step two is based on a solid-liquid ratio of 1g:5mL, and the concentration of H2SO4 is 5 mol / L. -1 After stirring, the product was washed three times each with deionized water and anhydrous ethanol. The centrifuged product was then dried in a 60 °C oven for 12 h. After drying, the product was ground for 30 min to obtain activated red mud (ARM).

4. The method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater according to claim 1, characterized in that, In step (2), the amount of NiCl2·6H2O in step one is 0.5-1 mol, which is dissolved in 40 mL of deionized water and stirred for 30 min.

5. The method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater according to claim 1, characterized in that, In step (2), the amount of activated red mud added in step two is 2 g, and the stirring time is 30 min.

6. The method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater according to claim 1, characterized in that, In step (2), step three involves adding 40 mL of 0.5 mol L... -1 NaOH solution.

7. The method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater according to claim 1, characterized in that, In step (2), the hydrothermal temperature in step four is 180 ℃, and the temperature is maintained for 12 h.

8. The method for preparing a red mud-based ARM / NiOOH adsorbent material for adsorbing dye wastewater according to claim 1, characterized in that, In step (2), the material is washed three times each with deionized water and anhydrous ethanol, and then dried at 60 °C for 12 h to obtain the ARM / NiOOH adsorbent material.

9. The red mud-based ARM / NiOOH adsorbent material prepared according to claim 1 is applied to the adsorption and removal of Congo red dye in wastewater.

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