JP-7854582-B1 - Double-embedded particles and their preparation method, and their application in the decomposition of estrogen in wastewater

Abstract

[Problem] To provide double-buried particles for wastewater treatment and their application in the decomposition of estrogen in wastewater. [Solution] Double-embedded particles are obtained by preparing artificial photosynthetic particles embedded with photocatalysts and white-rot fungi, and natural photosynthetic particles embedded with bacteria and green algae. The double-embedded particles have a good removal effect on bound estrogen and artificially synthesized free estrogen in wastewater. The double-embedded photosynthetic particles solve the problems of low decomposition efficiency of biological treatment and poor toxicity reduction effect of advanced oxidation treatment in existing technologies, and provide a new means of wastewater treatment. [Selection Diagram] None

Inventors

• 耿金菊
• 薛鴻普
• 張偉
• 于清▲みぃお▼
• 何玉潔
• 包毅
• 葛李

Assignees

• 重慶大学

Dates

Publication Date

20260507

Application Date

20250225

Priority Date

20241128

Claims (1)

1. A method for preparing double-embedded particles, The double-embedded particles consist of artificial photocatalytic particles and natural photosynthetic particles. The artificial photocatalytic particles include a calcium alginate hydrogel, a photocatalyst embedded in the calcium alginate hydrogel, and a white rot fungus, wherein the photocatalyst has an iron-based organometallic skeleton NH2 -MIL-53(Fe), The aforementioned natural photosynthetic particles include a calcium alginate hydrogel and green algae and Bacillus subtilis embedded in the calcium alginate hydrogel. The particle diameter of the artificial photocatalytic particles is 2 to 5 mm, and the particle diameter of the natural photosynthetic particles is 2 The size is ~5 mm, and the ratio of the number of artificial photocatalytic particles to natural photosynthetic particles is (1-6):(1 ~6 ) The method for preparing the double-embedded particles includes the following steps: S1. Preparation of artificial photocatalytic particles: Collect 25-50 mL of white rot fungal fluid with an OD600 of 0.8-1.0, and then 5000-7 The white rot fungal cells were obtained by centrifuging at 000 rpm for 9 to 11 minutes, and the white rot fungal cells were obtained. Dissolve 0.03-0.06 g of photocatalyst in 50-80 mL of sodium alginate solution at a mass concentration of 1-2%. Mix with the um solution and use a 2-5 mL syringe to dispense 50-100 mL of 2-5% C solution by mass. Add to aCl2 solution dropwise and allow to fixate for 30-60 min to obtain artificial photocatalytic particles. S2. Preparation of natural photosynthetic particles: Take 25-50 mL of green algae liquid with an OD680 of 0.8-1.0 and ferment at 4000-6000 rpm. Centrifugation was performed for 10-15 minutes at m to collect the green algae, and 25-50 mL of OD600 was added. Take a Bacillus subtilis solution with a concentration of 8-1.0 and disperse it for 10-15 minutes under conditions of 6000-8000 rpm. After separating the heart and recovering the Bacillus subtilis cells, The green algae and Bacillus subtilis cells are suspended in 5-8 mL of ultrapure water, and a mass concentration of 1 is added to 50-80 mL. Mix uniformly with a 2% sodium alginate solution to obtain a fungal-algal mixture, and the fungal-algal mixture Dispense the solution into 50-100 mL of a 2-5% CaCl2 solution using a 2-5 mL syringe. After grinding, a fixation reaction is carried out for 30-60 minutes to obtain natural photosynthetic particles. The method for preparing the white rot fungal solution is as follows: white rot fungal cells are transferred to a liquid jar. Inoculate into a complete culture medium for sweet potatoes, and at 28-32°C, the OD600 of the white rot fungus saturates to 0.8-1.0. The mixture is cultured until it reaches a certain stage, and a white rot fungal solution is obtained. The liquid potato mixture is 20% potato 1 liter of broth, 20 g of glucose, 3 g of KH2PO4, 1.5 g of MgSO4・7H2O It contains 1 g of thiamine and has a pH of 6. The method for preparing the aforementioned green algae solution is as follows: Green algae are inoculated into BG11 medium, and 24-26 Cultivate at °C and 2000 Lux for 1-2 weeks to obtain a green algae solution with an OD680 of 0.8-1.0. The green alga mentioned is Chlorella. The method for preparing the Bacillus subtilis bacterial suspension is as follows: Inoculate Bacillus subtilis into a nutrient-rich meat juice medium, and 28- Under conditions of 30°C and 120-130 rpm, the OD600 of the Bacillus subtilis bacterial solution becomes 0.8-1.0. The culture was continued until the nutrient broth medium consisted of 5.0 g peptone, 3.0 g beef extract, and NaCl. It contains 5.0 g and 1 L of distilled water, and the pH is 7.0 to 7.2. A method for preparing double-embedded particles, characterized by the features described above.

Description

This invention relates to the technical field of wastewater treatment, and more specifically to double-embedded particles, a method for preparing them, and their application in the decomposition of estrogen in wastewater. The operation of wastewater treatment plants by local governments faces new challenges and opportunities. Conventional secondary biochemical treatment processes are effective in reducing conventional pollution indicators and meeting basic environmental requirements, but they become ineffective when faced with highly toxic, bio-resistant, and difficult-to-decompose pollutants. Estrogen has long been widely studied and applied due to its special role in the body, but the ecological risks posed by its persistence and accumulation in the natural environment are gradually becoming apparent. In the field of wastewater treatment, advanced oxidation and biological enhancement technologies are two cutting-edge strategies for deeply purifying estrogens, which are difficult to decompose, each demonstrating its own advantages and limitations. First, advanced oxidation technologies have the double-edged sword of being fast reaction rates and highly efficient decomposition, but the decomposition products may pose more serious toxicity problems than the original pollutants, thus limiting their potential for widespread application. Biological enhancement technologies are particularly effective in reducing the toxicity of pollutants and contributing to environmental restoration and ecosystem balance. However, regarding the biological suppression of persistent pollutants, the decomposition efficiency of conventional biological enhancement technologies often falls short of expectations, and they often fail to exhibit their intended effect when used alone, which is a significant factor limiting their effectiveness. This invention employs the following technical solutions: This invention provides a dual-embedded particle consisting of artificial photosynthetic particles and natural photosynthetic particles. The artificial photosynthetic particles consist of a calcium alginate hydrogel, a photocatalyst embedded in the calcium alginate hydrogel, and a white rot fungus, the photocatalyst being an MOF material NH2 -MIL-53(Fe), The aforementioned natural photosynthetic particles consist of calcium alginate hydrogel and green algae and Bacillus subtilis embedded in the calcium alginate hydrogel. The particle diameter of the artificial photosynthetic particles is 2 to 5 mm, and the particle diameter of the natural photosynthetic particles is 2 to 5 mm. The dimensions are mm, and the ratio of the number of artificial photosynthetic particles to natural photosynthetic particles is (1-6):(1-6). In this invention, the principle of action of the artificial photosynthetic particles is that white rot fungi have the characteristic of secreting laccase. In the presence of white rot fungi, laccase (Lac) is generated within the system, the photocatalyst captures visible light and generates electrons, and the electrons move to T1 Cu(II) of the laccase to initiate an enzymatic reaction. Because an organic covalent bond system is formed between the photocatalyst and the laccase, the active site of the laccase and the catalytic activity of the laccase are enhanced, catalyzing the ring-opening and bond cleavage of estrogen, and allowing for the easy removal of mixed estrogens from pollutants. Green algae further remove mixed estrogens under photosynthesis, not only playing a role in reducing the effect of the generated estrogens but also producing oxygen for microbial respiration. Bacillus subtilis further decomposes the photocatalytically decomposed estrogen intermediates, producing CO2 for absorption by microalgae and various vitamins such as vitamins B1 and B2. In one aspect of the present invention, the method for preparing the photocatalyst is as follows: 1.08 to 2.02 Take g of FeCl3 · 6H₂O and 0.73-0.91 g of NH₂ - H₂BDC , and 50°C Dissolve in 80 mL of organic solvent and perform hydrothermal synthesis at 150-170°C for 18-24 hours under sealed conditions. After cooling, wash with an organic solvent to remove the organic solvent, and then remove the iron-based organometallic skeleton NH2 -MIL-53(F e) is obtained and used as the photocatalyst, where the organic solvent is N-N dimethylformamide. During the dissolution process, dissolution is preferably promoted by ultrasonic or magnetic stirring. During dissolution, 2-aminoterephthalic acid is preferably first dissolved in an organic solvent, and then ferric chloride is added. The hydrothermal synthesis is preferably carried out in a polytetrafluoroethylene reaction vessel. During washing, the reaction product is preferably cooled to room temperature (25°C). The washing can also be performed by repeating alternating washing with DMF and anhydrous ethanol and centrifugation three times. After washing, the obtained product is preferably dried. The drying temperature is preferably 70