CN-122010274-A - Gel-embedded slow-release oxygen material and preparation method thereof

Abstract

The invention relates to the technical field of eutrophic water and endogenous pollution treatment, and particularly discloses a preparation method of a gel-embedded slow-release oxygen material, which comprises the following steps of S1, mixing a stabilizer with a sodium alginate solution, and uniformly stirring to obtain an embedded precursor solution; the stabilizer comprises at least one of potassium chloride and polyvinylpyrrolidone, S2, mixing a porous material matrix loaded with oxygen with the embedding layer precursor solution, stirring and uniformly mixing to form uncrosslinked suspension, S3, dropwise adding the obtained uncrosslinked suspension into a metal salt solution, and carrying out curing reaction to obtain the gel embedded slow-release oxygen material. The invention also discloses a gel-embedded slow-release oxygen material, which is prepared by adopting the preparation method of the gel-embedded slow-release oxygen material. The technical problems that the existing oxygen-carrying porous material is easy to escape oxygen and can not be slowly released for a long time, and the pH of water body is influenced by byproducts existing in the chemical oxygen release agent are solved.

Inventors

• MA YUANYUAN
• LIU YI
• LI HONG
• ZHENG YUANLIN
• XU HAIJUN
• GUO XIANGYU

Assignees

• 重庆大学

Dates

Publication Date

20260512

Application Date

20260226

Claims (10)

1. 1. The preparation method of the gel-embedded slow-release oxygen material is characterized by comprising the following steps of: S1, mixing a stabilizer and a sodium alginate solution, and stirring and uniformly mixing to obtain an embedding layer precursor solution, wherein the stabilizer comprises at least one of potassium chloride and polyvinylpyrrolidone; s2, mixing the porous material matrix loaded with oxygen with the embedding layer precursor solution, and stirring and uniformly mixing to form uncrosslinked suspension; S3, dropwise adding the obtained uncrosslinked suspension into a metal salt solution, and performing curing reaction to obtain the gel-embedded slow-release oxygen material.
2. 2. The method for preparing the gel-embedded slow-release oxygen material according to claim 1, wherein the concentration of the potassium chloride solution is 0.045%, and the adding proportion is that 2mL of the potassium chloride solution is added to every 100mL of the sodium alginate solution.
3. 3. The preparation method of the gel-embedded slow-release oxygen material according to claim 1, wherein the concentration of the polyvinylpyrrolidone solution is 1-8% w/v, and the adding proportion is that 3mL of polyvinylpyrrolidone solution is added to every 100mL of sodium alginate solution.
4. 4. The method for preparing the gel-embedded slow-release oxygen material according to claim 3, wherein the concentration of the polyvinylpyrrolidone solution is 3-5% w/v.
5. 5. The method for preparing a gel-embedded slow release oxygen material according to claim 1, wherein in the step S2, the porous material matrix loaded with oxygen is prepared by a vacuum pressure swing adsorption method; The vacuum pressure swing adsorption method is to put a porous material matrix into a high-pressure vacuum pump for vacuumizing, and then open an O 2 valve for carrying oxygen after closing a vacuum valve, and circularly vacuumizing and carrying oxygen for a plurality of times.
6. 6. The method for preparing a gel-embedded slow-release oxygen material according to claim 5, wherein the mixing volume ratio of the oxygen-loaded porous material matrix to the embedded precursor solution is 1:1.25-1:2.
7. 7. The method of claim 6, wherein in the step S3, the metal cations in the metal salt solution include at least one of Ca 2+ 、Zn 2+ 、Fe 3+ , and the mass concentration of the metal salt solution is 0.3-1% w/v.
8. 8. The method for preparing a gel-embedded slow-release oxygen material as claimed in claim 7, wherein the metal salt solution is a soluble chloride salt solution.
9. 9. The method for preparing the gel-embedded slow release oxygen material according to claim 1, wherein the step S3 is performed with a curing reaction, and the method further comprises the steps of filtering and washing with deionized water.
10. 10. A gel-embedded sustained-release oxygen material characterized by being prepared by the preparation method of the gel-embedded sustained-release oxygen material according to any one of claims 1 to 9.

Description

Gel-embedded slow-release oxygen material and preparation method thereof Technical Field The invention relates to the technical field of eutrophic water and endogenous pollution treatment, in particular to a gel-embedded slow-release oxygen material and a preparation method thereof. Background Endogenous pollution is an important source in the eutrophication process of water, and mainly refers to nutrient substances such as nitrogen, phosphorus and the like released by sediment. The release of the endogenous pollution is effectively controlled, and the method has important significance for treating the eutrophication of the water body. The dissolved oxygen content of the sediment-water interface can change the oxidation-reduction potential at the interface, thereby affecting the conversion of the two-phase nitrogen and phosphorus morphology and directly affecting the nitrogen and phosphorus release process of the sediment. Therefore, the dissolved oxygen concentration of the water body, especially the dissolved oxygen concentration of sediment-water interface, can inhibit the release of endogenous pollutants and control the eutrophication of the water body. At present, the technology of oxygen release in endogenous pollution treatment mainly comprises two types, namely a chemical oxygen release agent embedding method and a porous material oxygen-loaded nano bubble method. 1. Embedding method of chemical oxygen releasing agent The chemical oxygen release agent embedding method is to compound solid oxygen release agents such as calcium peroxide (CaO 2), magnesium peroxide (MgO 2) and the like with coating materials such as alginate and the like, form gel materials through ionic crosslinking, and utilize the physical barrier of a gel layer to delay the contact of the oxygen release agents and water so as to realize slow oxygen release. For example, patent publication No. CN109574184A discloses a sustained-release oxygen cation cross-linking agent and a preparation method thereof, wherein calcium peroxide/magnesium peroxide is used as a sustained-release oxygen source, sodium alginate is used as a coating agent, bentonite is used as an additive, and a sustained-release oxygen gel material is prepared by a dropping ball process. The material can delay the oxygen release rate to a certain extent and improve the oxygen utilization rate. However, the chemical oxygen release agent embedding method has the inherent defects that when oxygen release agents such as calcium peroxide, magnesium peroxide and the like react with water to generate oxygen, the pH value of water body is increased, the aquatic ecosystem is impacted, and the metabolic activity of bottom mud microorganisms is affected. 2. Oxygen nano bubble loading method for porous material The porous material oxygen-carrying nano bubble method is to place porous material (such as biochar, molecular sieve, diatomite, etc.) in high pressure oxygen environment, and to load oxygen into pores by physical adsorption to form oxygen-carrying porous material. When in use, oxygen is released from the pores, thus realizing the purpose of oxygenation. The method is a pure physical process, has no chemical byproducts and is excellent in environmental friendliness. However, the porous material oxygen-loaded nano bubble method faces serious challenges in practical application, namely small molecular size and large diffusion coefficient of oxygen, and once the oxygen-loaded porous material is separated from a high-pressure environment, adsorbed oxygen is very easy to escape rapidly, so that oxygen is lost rapidly, and the method is not suitable for the situation requiring long-acting oxygen release. At present, the problem of oxygen retention of the oxygen-carrying porous material is not solved in the field, and the application of the oxygen-carrying porous material in practical engineering is restricted. Sodium alginate is a natural polysaccharide and has the characteristics of low economic cost, high cost performance, environmental protection, good biocompatibility, biodegradability and the like. One skilled in the art has tried to adjust and control the release rate of substances by using sodium alginate gel embedding technology, for example, patent publication No. CN115637156a discloses a core-shell structure oxidizer slow release material, which uses porous material pre-adsorbed solid oxidizer (such as persulfate) as an inner core, and sodium alginate gel embedding additional oxidizer as an outer shell, for in-situ chemical oxidation remediation of soil/groundwater chlorinated hydrocarbon pollution. However, the technical scheme aims at realizing chemical oxidative degradation by dissolving and diffusing the solid chemical oxidant, and if the solid chemical oxidant is applied to eutrophic water and endogenous pollution control, the solid chemical oxidant still brings byproducts to influence the pH of the water and influence an ecological system. Disclosure of Invention Th