Preparation method and application of acid modified activated alumina ball adsorbent

Abstract

The invention relates to a preparation method and application of an acid-modified activated alumina ball adsorbent. The method comprises the following steps: dipping an activated alumina ball in an acid solution for 1-30 hours, then taking out, washing and drying to obtain an acid modified activated alumina ball adsorbent; the adsorbent is used for adsorption of organic anionic dyes, and can be regenerated and cyclically applied for multiple times. The adsorbent disclosed by the invention is easy to separate and good in regeneration performance, can maintain a relatively good adsorption effect after regeneration, and can efficiently, quickly and selectively adsorb anionic dyes in industrial wastewater.

Description

Technical Field

[0001] The invention relates to the field of adsorbents, and in particular to an application method of an acid-modified activated alumina ball adsorbent in dye wastewater treatment. Background Art

[0002] Water is the source of life and is essential for maintaining the balance of the ecosystem and the development of human society. In industries such as textiles, printing and dyeing, papermaking, plastics and pharmaceuticals, a large amount of organic wastewater with stable structure, high chroma and difficult biodegradability will be produced, which will lead to water quality deterioration, ecosystem damage, and even affect human health through accumulation in the food chain. Anionic dyes have been widely used in many industries such as textiles, printing and dyeing, food, cosmetics, plastics and paper due to their unique chemical properties and rich colors. However, this wide application has also brought serious environmental problems. In the industrial production process, a large amount of wastewater containing anionic dyes is discharged without sufficient treatment, resulting in water pollution and affecting the living environment of aquatic organisms. In addition, anionic dyes may also cause harm to human health. Therefore, how to effectively treat wastewater containing anionic dyes has become one of the important challenges currently faced.

[0003] At present, the main methods for removing organic dyes from wastewater are adsorption, biodegradation and advanced oxidation. Among them, adsorption is widely used in organic wastewater treatment due to its simple operation, low cost and high efficiency. Although progress has been made in adsorption materials and processes, there are still some challenges. For example, the adsorbents used in traditional physical adsorption methods are mostly powdered, which makes them difficult to separate, have low recycling efficiency, and are prone to secondary pollution. The regeneration and recovery of adsorbents are difficult, which limits the promotion and application of this technology. Therefore, it is necessary to further explore efficient and economical adsorbents to achieve efficient and sustainable treatment of anionic dye wastewater. Summary of the invention

[0004] The present invention aims at the problems that the current powdered adsorbents are difficult to separate, have low recycling efficiency, and are prone to secondary pollution, and provides a method for applying an acid-modified activated alumina ball adsorbent in dye wastewater treatment. This method is the first to use acid-modified activated alumina balls as adsorbents for the adsorption, regeneration and multiple recyclable applications of organic anionic dyes. The adsorbent is a spherical adsorbent, which is easy to separate, has good regeneration performance, and can maintain a good adsorption effect after regeneration, and can efficiently and quickly selectively adsorb anionic dyes in industrial wastewater.

[0005] The technical solution of the present invention is:

[0006] A method for preparing an acid-modified activated alumina ball adsorbent, the method comprising the following steps:

[0007] At 273K-373K, the activated alumina ball is immersed in an acid solution for 1h-30h, then taken out, washed with distilled water until the washing solution is neutral, and then dried at 313K-393K for 2h-14h to obtain an acid-modified activated alumina ball adsorbent;

[0008] The acid solution is one or more of nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid and oxalic acid;

[0009] The volume percentage concentration of the acid solution is 0.1%-40%.

[0010] The diameter of the activated alumina ball is 3-5 mm.

[0011] The acid-modified activated alumina ball adsorbent prepared by the method is used as an organic dye adsorbent in organic wastewater.

[0012] The application method comprises the following steps:

[0013] Acid-modified activated alumina ball adsorbent was added to organic dye wastewater with a pH value of 2-12, and stirred at 273-318K for 10-100 minutes to complete the adsorption;

[0014] The input amount of the acid-modified activated alumina ball adsorbent is 1-100 g / L;

[0015] The concentration of organic dye in the wastewater is 10 mg / L-200 mg / L;

[0016] The organic dye is one or more of golden orange II, methyl orange, reactive black 5, Congo red, acid blue and acid yellow.

[0017] The acid-modified activated alumina ball adsorbent has a removal rate of 22%-99% for organic dyes;

[0018] The application method also includes a desorption step: filtering and taking out the acid-modified activated alumina ball adsorbent, drying it, putting it into a desorbent solution, stirring it for 10-100 minutes, taking it out, washing it, and completing the desorption.

[0019] The desorbent is one or more of acid, alkali, alcohol and deionized water; the concentration of the desorbent in the solution is 0.1%-80%; 5g-300g of acid-modified activated alumina balls are added per liter of desorbent solution;

[0020] The acid is one or more of hydrochloric acid, formic acid, oxalic acid, sulfuric acid, acetic acid, propionic acid and nitric acid; the alkali is one or more of sodium hydroxide, ammonia water, calcium hydroxide, sodium carbonate, sodium bicarbonate and potassium hydroxide; the alcohol is one or more of methanol, ethanol, propanol, butanol, ethylene glycol and glycerol.

[0021] The application method further comprises a regeneration step:

[0022] The acid-modified activated alumina balls after desorption are placed in an acid solution and stirred for 10-100 minutes for regeneration. After being taken out, they are washed and dried.

[0023] The acid solution is one or more of oxalic acid, nitric acid, hydrochloric acid, sulfuric acid and phosphoric acid.

[0024] The volume percentage concentration of the acid solution is 0.1%-40%.

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention is the first to use acid-modified activated alumina ball adsorbent in the treatment of dye wastewater. Its high porosity and positive charge (such as Figure 2 As shown in the figure, it is beneficial to the adsorption of anionic dyes, and can efficiently and quickly adsorb anionic dyes in wastewater within a wide pH range (pH 2-10).

[0027] (2) Compared with powdered adsorbents, activated alumina balls have high strength and good wear resistance, and can maintain structural integrity in high-pressure and high-flow industrial environments without breaking or pulverizing. This makes them extremely low in loss during use, durable, and widely available, simple to prepare, highly chemically stable, easy to separate, and convenient to operate.

[0028] (3) The acid-modified activated alumina ball adsorbent used in the present invention has a good adsorption effect on anionic dyes and a rapid effect, and the removal rate can reach up to 99% within 40 minutes.

[0029] (4) The regeneration and reuse characteristics of the activated alumina balls used in the present invention make them excellent in environmental protection. The desorption and regeneration process is short, with a minimum of 20 minutes, which reduces the generation of waste and reduces the impact on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a SEM image of the acid-modified activated alumina ball adsorbent obtained in Example 3;

[0031] Figure 2 The Zeta potential diagram of the acid-modified activated alumina ball adsorbent obtained in Example 3 at different pH values; DETAILED DESCRIPTION

[0032] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the preparation of an acid-modified activated alumina ball adsorbent proposed by the present invention and its specific implementation method, characteristics and performance in combination with the preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0033] The acid-modified activated alumina ball adsorbent used in the present invention can selectively remove anionic dyes from mixed dyes quickly and efficiently, and has the advantages of being easy to separate, recycle and regenerate. Compared with powdered adsorbents, it is more suitable for the treatment of actual dye wastewater.

[0034] The specific steps for adsorption performance determination are as follows:

[0035] Use a UV-visible spectrophotometer to scan the entire band to obtain the maximum absorption wavelength of the dye in the solution. Prepare simulated dye wastewater solutions with different concentration gradients, measure their absorbance at their maximum absorption wavelength, and draw a standard curve. Use hydrochloric acid and sodium hydroxide solutions to adjust the pH value of simulated organic dye wastewater, add modified activated alumina balls of different masses to a certain concentration of simulated dye wastewater, stir at different temperatures, take samples at regular intervals, measure their absorbance after filtration, calculate the removal rate, and use a desorbent to perform desorption and regeneration experiments on the acid-modified activated alumina ball adsorbent after adsorption.

[0036] The calculation formulas for the adsorption amount, removal rate and desorption rate of various dyes are as follows:

[0037]

[0038] where q e (mg / g -1 ) is the equilibrium adsorption capacity; C0 and Ce (mg / L) are the initial concentration and equilibrium concentration respectively; V (L) is the volume of the dye; m (g) is the amount of adsorbent; R (%) is the removal rate; m (g) - the mass of adsorbate desorbed from the adsorbent; m c (g) – the mass of adsorbate on the adsorbent before desorption; D (%) is the desorption rate.

[0039] The activated alumina balls are known materials, Henan Tongxin New Materials Co., Ltd., KA401;

[0040] The following is a specific implementation description of the present invention, but it is not limited to the present invention.

[0041] Example 1

[0042] Preparation method of modified activated alumina ball adsorbent: screen activated alumina balls with a diameter of 3-5 mm, dry them at 333K for standby use. Prepare a sulfuric acid solution with a volume fraction of 10%, drip the sulfuric acid solution onto the activated alumina balls until the activated alumina balls are immersed, immerse for 9 hours, take out and wash with deionized water until the filtrate is neutral, dry at 353K for 4 hours, and obtain an acid-modified activated alumina ball anion dye adsorbent.

[0043] An adsorption experiment was carried out using simulated dye wastewater containing Golden Orange II: 100 mL of a 50 mg / L simulated dye wastewater solution was prepared, the pH was adjusted to about 8, the amount of adsorbent was 2 g, and it was stirred at room temperature and pressure. The removal rate could reach 40% in 40 minutes.

[0044] Sodium hydroxide solution was used as the desorbent, the mass percentage concentration of the sodium hydroxide desorbent was 4%, the desorption time was 1 hour, and after completion, the solution was taken out for cleaning and drying, and the desorption rate was 85%.

[0045] Example 2

[0046] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 1, except that the acid is a nitric acid solution. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 1, and the removal rate can reach 90%.

[0047] The desorption and regeneration experimental procedures were the same as in Example 1. Adsorption and desorption experiments were carried out under the same conditions, and the desorption rate was 83%.

[0048] Example 3

[0049] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 2, except that the acid is a hydrochloric acid solution with a volume fraction of 20%. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 2.

[0050] like Figure 2 As shown, at a pH value of 8, the surface of the modified activated alumina spheres is positively charged, and the removal rate of anionic dyes can reach 99%.

[0051] The desorption and regeneration experimental procedures were the same as in Example 2. Adsorption and desorption experiments were carried out under the same conditions, and the desorption rate was 85%.

[0052] Example 4

[0053] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 3. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 3, and the removal rate can reach 99%.

[0054] The desorption and regeneration experimental steps are the same as those in Example 3, except that an aqueous ammonia solution is used as the desorbent, the mass percentage concentration of the aqueous ammonia desorbent is 3.5%, the desorption time is 1 h, and the desorption rate is 97%.

[0055] Example 5

[0056] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 4. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 4, except that 100 mL of 50 mg / L reactive black 5 dye is selected in the simulated dye wastewater, and the removal rate can reach 96%.

[0057] The desorption and regeneration experimental steps were the same as in Example 4, and the desorption rate was 95%.

[0058] Example 6

[0059] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 5. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 5, except that 100 mL of methyl orange dye with a concentration of 50 mg / L is selected in the simulated dye wastewater, and the removal rate can reach 90%.

[0060] The desorption and regeneration experimental steps were the same as in Example 5, and the desorption rate was 92%.

[0061] Example 7

[0062] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 4. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 4, except that 100 mL of 100 mg / L golden orange II dye is selected in the simulated dye wastewater, and the removal rate can reach 95%.

[0063] The desorption and regeneration experimental steps were the same as in Example 5, and the desorption rate was 90%.

[0064] Example 8

[0065] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 4. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 4, except that 100 mL of 200 mg / L golden orange II dye is selected as the simulated dye wastewater, and the removal rate can reach 82%.

[0066] The desorption and regeneration experimental steps were the same as in Example 5, and the desorption rate was 85%.

[0067] Example 9

[0068] The other steps of preparing the acid-modified activated alumina ball adsorbent are the same as those in Example 4. The other steps of the adsorption experiment of simulated dye wastewater are the same as those in Example 4, except that the amount of adsorbent used is 1.6 g, and the removal rate can reach 89%.

[0069] The desorption and regeneration experimental steps were the same as in Example 5, and the desorption rate was 95%.

[0070] The preferred embodiments of the present invention are described in detail above, but are not limited thereto. In the present invention, there may be many simple transformation combinations, including individual technical features, which may be combined in any other appropriate manner, and they should also be regarded as within the scope of the present invention and are within the protection scope of the present invention.

[0071] Matters not covered by the present invention are known technologies.

Claims

1. A method for preparing an acid-modified activated alumina ball adsorbent, characterized in that: The method comprises the following steps: At 273K-373K, the activated alumina ball is immersed in an acid solution for 1h-30h, then taken out, washed with water until the washing solution is neutral, and then dried at 313K-393K for 2h-14h to obtain an acid-modified activated alumina ball adsorbent; The acid solution is one or more of nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid and oxalic acid; The volume percentage concentration of the acid solution is 0.1%-40%.

2. The method for preparing the acid-modified activated alumina ball adsorbent according to claim 1, characterized in that: The diameter of the activated alumina ball is 3-5 mm.

3. The application method of the acid-modified activated alumina ball adsorbent prepared by the method as claimed in claim 1, characterized in that it is used as an organic dye adsorbent in organic wastewater.

4. The application method according to claim 3, characterized in that it comprises the following steps: Acid-modified activated alumina ball adsorbent was added to organic dye wastewater with a pH value of 2-12, and stirred at 273-318K for 10-100 minutes to complete the adsorption; The input amount of the acid-modified activated alumina ball adsorbent is 1-100 g / L; The concentration of organic dye in the wastewater is 10 mg / L-200 mg / L; The organic dye is one or more of golden orange II, methyl orange, reactive black 5, Congo red, acid blue and acid yellow.

5. The application method according to claim 4, characterized in that it also includes a desorption step: filtering and removing the acid-modified activated alumina ball adsorbent, drying it, placing it in a desorbent solution, stirring it for 10-100 minutes, taking it out, washing it, and completing the desorption; The desorbent is one or more of acid, alkali, alcohol and deionized water; the concentration of the desorbent in the solution is 0.1%-80%; 5g-300g of acid-modified activated alumina balls are added per liter of desorbent solution; The acid is one or more of hydrochloric acid, formic acid, oxalic acid, sulfuric acid, acetic acid, propionic acid and nitric acid; the alkali is one or more of sodium hydroxide, ammonia water, calcium hydroxide, sodium carbonate, sodium bicarbonate and potassium hydroxide; the alcohol is one or more of methanol, ethanol, propanol, butanol, ethylene glycol and glycerol.

6. The application method according to claim 5, characterized in that: The application method further comprises a regeneration step: The acid-modified activated alumina balls after desorption are placed in an acid solution and stirred for 10-100 minutes for regeneration, and then taken out, washed and dried; The acid solution is one or more of oxalic acid, nitric acid, hydrochloric acid, sulfuric acid and phosphoric acid; The volume percentage concentration of the acid solution is 0.1%-40%.

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