Adsorbent beads

Abstract

The present invention relates to a green production process to produce metal organic biocomposites suitable for the separation of cationic dyes, such as methylene blue, from aqueous environmental contaminants by an adsorption process.

Description

Technical Field

[0001] The present invention relates to a green production method for producing metal organic biocomposites suitable for separating cationic dyes (such as methylene blue) from environmental pollutants in aqueous environments by adsorption. Background Art

[0002] The existing technologies include various biocomposites that impart dye selectivity through magnetism, reuse, and surface modification.

[0003] For example, Xiaoshu Lv et al. 3 O 4 nanocomposites embedded polyvinylalcohol / sodium alginate beads for chromium(VI)removal, 3 O 4 This is disclosed in “Polyvinyl alcohol / sodium alginate beads embedded in nanocomposite materials” Journal of Hazardous Materials, Vol. 262, November 15, 2013, pp. 748-758 and Vincent Rocher et al. in their article “Removal of organic dyes by magnetic alginate beads”, Water Research, Vol. 42, No. 4-5, February 2008, pp. 1290-1298.

[0004] However, existing technologies do not include durable, spherical, micrometer-sized biocomposites produced using green manufacturing methods that combine magnetism, cationic dye selectivity, and reuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 :Production method flow chart DETAILED DESCRIPTION

[0006] The adsorbent beads obtained by the present invention have different water absorption rates (swelling rates) in aqueous solutions of different pH values. Based on this characteristic, it can be used as a waterproof material and can be reused.

[0007] The method for producing the adsorbent beads of the present invention comprises the following basic steps.

[0008] A water extract obtained from the leaf bark of the aloe vera plant was used to produce magnetic iron oxide nanoparticles. After treatment, the beads acquired magnetic properties and the possibility of separating them from water using an external magnet was obtained.

[0009] · The magnetic iron oxide nanoparticle solution and the alginate solution were mixed and dropped into the calcium chloride solution to produce micrometer-sized spherical beads.

[0010] The surface of the beads was modified by coating with chitosan and soaking in 0.1 M hydrochloric acid. In this way, the beads did not swell in water, did not lose their shape, were selective for cationic dyes (such as methylene blue), and could be reused.

[0011] Production method

[0012] Synthesis of Iron Oxide Nanoparticles (FeONP)

[0013] The leaf bark of the aloe vera plant is used for green synthesis. 3 Dissolved in water as a precursor material to prepare iron oxide nanoparticles.

[0014] - The leaf skin of the aloe vera plant was cut into small pieces and extracted in purified water. The aloe vera plant was chosen due to its high content of minerals, polyphenols and vitamins.

[0015] - Separate the aloe vera plant aqueous extract from the pulp by filtering through Whatman No. 1 filter paper.

[0016] - Preparation of 3%-4% ferric chloride (FeCl 3 It was used as a precursor for nanoparticle synthesis.

[0017] - Mixing the aloe vera plant extract into the iron solution. After reacting for 2-4 hours, the colloidal iron oxide nanoparticle solution obtained has a pH value of 10-12, and the precipitate is the iron oxide nanoparticle.

[0018] Synthesis of Alginate (Alg)-Iron Oxide Nanoparticles (FeONP)

[0019] To synthesize the hydrogel beads, a 2-3 wt% alginate solution was prepared. The iron oxide nanoparticles and the alginate solution were mixed in a 1:1 ratio. Preferably, the mixing ratio is 1:1. The mixing ratio affects the viscosity of the mixture and affects the formation of spherical hydrogel beads. The formation of a spherical shape allows the beads to obtain the maximum surface area. This provides the maximum reaction area.

[0020] Synthesis of Calcium (Ca)-Alg-FeONP Beads

[0021] To obtain spherical hydrogel beads, the Alg-FeONP mixture was dropwise mixed into 2-3% by weight CaCl 2 The obtained spherical hydrogel beads were placed in CaCl 2 The solution is kept for 22-24 hours to improve its structural stability. 2 The solution was selected as Ca +2 Ion source. The literature indicates that the cross-linking gelation effect in calcium chloride solution is better than other solutions (calcium gluconate, calcium nitrate, calcium propionate). The beads are air-dried at room temperature to keep their spherical shape and not be damaged. The air-drying process is very important because when the beads are subjected to different deep freezing and vacuum methods at +4 degrees and -19 degrees, they shrink and lose their spherical shape.

[0022] Synthesis of Magnetic Green Adsorbent Microparticles

[0023] The Ca-Alg-FeONP beads were placed in a beaker containing a 0.1-0.2M hydrochloric acid (HCl) solution and left to stand for 10-12 hours, so that the calcium in its structure reacted with HCl and released hydrogen, and a porous structure was formed on the surface of the beads, which had a favorable effect on the adsorption capacity of the beads. The molar concentration of the hydrochloric acid solution was 0.1-0.2. Low molar concentrations did not destroy the structure of the beads. The HCl substance reacted with the Ca ions loaded in the bead structure, releasing gas to form a porous structure.

[0024] The beads were then placed in a beaker containing 2-3 wt% chitosan solution and mixed at low speed for 3-4 hours. The chitosan coating forms a dual-acting gel structure that allows the magnetic bead material to be reused. Chitosan was chosen because it is a biodegradable substance. In addition, it was observed that the chitosan-coated beads could be reused without damaging their surface structure.

[0025] Finally, the beads were washed with distilled water and stored in 0.1 M HCl solution, thereby ensuring the selectivity of the functional groups on the bead surface for cationic dyes.

Claims

1. A method for producing adsorbent beads, characterized in that The following steps are involved: a. Using water extract obtained from the leaf bark of the aloe plant to produce magnetic iron oxide nanoparticles, b. by mixing the magnetic iron oxide nanoparticle solution with the alginate solution and dropping it into the calcium chloride solution to produce micron-sized spherical beads, c. The surface of the beads was modified by coating with chitosan and soaking in 0.1-0.2 M hydrochloric acid.

2. The method according to claim 1, characterized in that The method comprises the following steps: a. extracting small pieces of the aloe plant leaf skin in purified water; b. Prepare 3-4wt% FeCl3 solution; c. mixing the aloe plant extract into the FeCl3 solution; d. adjusting the pH value of the obtained colloidal iron oxide nanoparticle solution to 10-12; e. mixing the obtained colloidal iron oxide nanoparticle solution with 2-3wt% alginate solution in a ratio of 1:1; f. The mixture is added dropwise to a 2-3% by weight CaCl2 solution; g. The beads were air-dried at room temperature; h. The beads were soaked in 0.1 M hydrochloric acid solution, 2-3% chitosan solution, and then soaked in 0.1 M hydrochloric acid solution again.

3. An adsorbent bead, characterized in that The adsorbent beads are produced by the method according to claim 1 or 2.

4. The adsorbent bead according to claim 3, characterized in that The beads are cationic dye selective.

5. Use of the adsorbent beads according to claim 3 for separating cationic dyes from water.

6. The use according to claim 5, characterized in that The cationic dye is methylene blue.

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