A cellulose-based composite bead for activating persulfate-degrading dyes and its preparation method
By preparing cellulose-based composite bead CS-Ca@PEI/CuMnO2 catalyst, the problems of difficult recycling and secondary pollution of metal ion catalysts were solved, achieving efficient and environmentally friendly degradation of organic dyes, and suitable for wastewater treatment with a wide pH range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUILIN UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2023-10-13
- Publication Date
- 2026-05-26
AI Technical Summary
Existing metal ion catalysts are difficult to recycle when degrading organic pollutants, which can easily cause secondary environmental pollution. Furthermore, the traditional Fenton technology has poor degradation efficiency over a wide pH range.
Using cellulose-based composite beads CS-Ca@PEI/CuMnO2 as catalysts, CuMnO2 was prepared via a solvothermal method and crosslinked with cellulose, sodium alginate, and polyethyleneimine to form macroscopic spherical catalysts. These catalysts were used to activate persulfate degradation dyes. The process was simple and applicable to a wide pH range.
It achieves easy recycling of the catalyst, fast degradation rate, high degradation rate, and is suitable for the degradation of organic dyes in a wide pH range, avoiding the secondary pollution problem of metal ion catalysts.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of wastewater treatment, specifically relating to a cellulose-based composite bead for activating persulfate-degrading dyes, its preparation method, and its application. Background Technology
[0002] In recent years, the large amount of organic pollutants in the aquatic environment, such as dye molecules, antibiotics, and pesticides, has attracted much attention and has had a certain impact on people's lives. Therefore, it is crucial to find a highly efficient, environmentally friendly, and sustainable technology for degrading high concentrations of organic pollutants. Among these technologies, advanced oxidation technology (AOP) is particularly important. S As a cutting-edge technology for removing recalcitrant organic pollutants, persulfate has received widespread attention in the field of environmental remediation. Heterogeneous Fenton-like technologies utilizing persulfate as an oxidant have gradually developed into powerful techniques for degrading recalcitrant and non-biodegradable pollutants in wastewater. However, the leakage and irreversibility of metal compound ions, along with their difficulty in recycling, can easily cause secondary environmental pollution, thus limiting the practical application of Fenton-like technologies. Summary of the Invention
[0003] This invention aims to solve the problem of efficient degradation of organic dyes in industrial wastewater. Addressing the technical problems and shortcomings of existing metal ion catalysts, it proposes a method for preparing cellulose-based composite beads for activating persulfate-based dye degradation. These cellulose-based composite beads are macroscopically spherical, easily recyclable, and solve the problems of difficult recycling and secondary environmental pollution caused by existing metal ion catalysts. Furthermore, this catalyst can efficiently degrade organic dyes over a wide pH range, the process is simple to operate, and the catalytic degradation occurs at room temperature, in darkness, or under natural light conditions, making it suitable for widespread application.
[0004] The specific steps of this invention are as follows:
[0005] (1) Preparation of CuMnO2: First, copper and manganese sources were added to an organic solvent at a mass ratio of (0.01–1%):(0.01–1%):1. Sodium hydroxide and citrate were added to deionized water at a mass ratio of (0.02–1%):(0.01–1%):1, and stirred at 25–60 °C for 1.0–2.0 h. Then, the copper source solution was added to the manganese source solution, followed by sodium citrate and sodium hydroxide solutions. The mixture was stirred for 0.5–2.0 h and then transferred to a reaction vessel. The reaction was carried out under solvothermal conditions for a period of time. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain CuMnO2.
[0006] The copper source can be selected from one of copper chloride, copper acetate, and copper nitrate; the manganese source can be selected from one of manganese chloride, manganese acetate, and manganese nitrate; the molar ratio of copper source to manganese source is 1:1.
[0007] The organic solvent is polyethylene glycol or polypropylene glycol.
[0008] The concentration of the copper source solution is 0.05–0.5 M, and the concentration of the manganese source solution is 0.05–0.5 M.
[0009] The solvothermal reaction temperature is 100-200℃ and the time is 10-15h; preferably, the reaction is carried out at 130℃ for 10h.
[0010] (2) Preparation of CS-Ca@PEI / CuMnO2 composite beads: First, cellulose, sodium alginate, polyethyleneimine, and CuMnO2 were added to deionized water and stirred evenly. The mass ratio of each drug to deionized water was (0.01-10%):(0.01-10%):(0.02-10%):(0.01-10%):1. The mixture was stirred at 25-60℃ for 6.0-24.0 h. Then, the mixed solution of cellulose, sodium alginate, polyethyleneimine, and CuMnO2 was added dropwise to a calcium ion or iron ion crosslinking solution for 1.0-2.0 h. The mixture was then immersed in glutaraldehyde solution at a crosslinking temperature of 25-60℃ for 2.0-6.0 h to prepare CS-Ca@PEI / CuMnO2 composite beads.
[0011] (3) The prepared cellulose-based composite beads are used to activate persulfate for the degradation of dyes. The catalyst and persulfate are added to the wastewater containing organic dyes, and the persulfate can be catalytically activated to degrade organic dyes under natural light conditions.
[0012] The organic dye is one or a mixture of Congo Red, methyl orange, or Rhodamine B.
[0013] The amount of CS-Ca@PEI / CuMnO2 catalyst added is 0.5 g / L to 2 g / L, and the amount of persulfate added is 0.5 mM to 2 mM;
[0014] The concentration of the wastewater containing reactive dyes is 50 mg / L-200 mg / L; the degradation time is 10 min-90 min. The beneficial effects of this invention are:
[0015] (1) The CuMnO2 preparation process of the present invention is simple, does not require special atmosphere protection, and has high specific surface area and special spherical morphology.
[0016] (2) The CS-Ca@PEI / CuMnO2 composite bead catalyst of the present invention has excellent degradation performance of persulfate on dye wastewater, with fast degradation speed and high degradation rate.
[0017] (3) The CS-Ca@PEI / CuMnO2 composite beads of the present invention have the advantages of simple preparation process, easy mass production, and easy recovery of macroscopic spherical catalyst. They effectively solve the problems of metal ion solution catalytic systems or powder catalysts that are difficult to recycle and reuse, and easy to cause secondary pollution in the prior art. Attached image description:
[0018] Figure 1 This is a SEM image of CuMnO2 obtained in Example 1 of the present invention;
[0019] Figure 2 This is a SEM image of the CS-Ca@PEI / CuMnO2 composite beads obtained in Example 4 of the present invention;
[0020] Figure 3 The XRD spectra of CuMnO2 and CS-Ca@PEI / CuMnO2 obtained in Examples 1 and 4 of this invention are shown below.
[0021] Figure 4 Degradation effect of CS-Ca@PEI / CuMnO2 composite beads obtained in Example 4 on Congo red under different catalytic systems;
[0022] Figure 5 The degradation effect of CS-Ca@PEI / CuMnO2 composite beads obtained in Example 4 on Congo red under different pH conditions; Detailed implementation method:
[0023] To further understand the present invention, specific embodiments of the present invention are described in detail below with reference to the technical solutions and accompanying drawings, but this does not imply any limitation on the present invention.
[0024] Preparation of CuMnO2:
[0025] Example 1:
[0026] The preparation steps for CuMnO2 are as follows:
[0027] Add 1.23g of copper acetate and 0.50g of manganese acetate to 100mL of deionized water, then add 50mL of polyethylene glycol, stir at 25℃ for 60min, then add 1.20g of sodium hydroxide and 2g of citrate, continue stirring for 60min, transfer to a reaction vessel and heat at 130℃ for 10h, the reaction is complete.
[0028] Example 2:
[0029] The preparation steps for CuMnO2 are as follows:
[0030] Add 1.23g of copper acetate and 0.50g of manganese acetate to 100mL of deionized water, then add 50mL of polypropylene glycol, stir at 25℃ for 60min, then add 1.20g of sodium hydroxide and 2g of citrate, continue stirring for 60min, transfer to a reaction vessel and heat at 130℃ for 10h, the reaction is complete.
[0031] Example 3:
[0032] The preparation steps for CuMnO2 are as follows:
[0033] Add 1.23g of copper acetate and 0.50g of manganese chloride to 100mL of deionized water, then add 50mL of polyethylene glycol, stir at 25℃ for 60min, then add 1.20g of sodium hydroxide and 2g of citrate, continue stirring for 60min, transfer to a reaction vessel and heat at 130℃ for 10h, the reaction is complete.
[0034] Preparation of CS-Ca@PEI / CuMnO2 composite beads
[0035] Example 4:
[0036] The preparation steps for CS-Ca@PEI / CuMnO2 composite beads are as follows:
[0037] 0.5 g of nanocellulose, 0.5 g of alginate, and 1.5 g of polyethyleneimine were dissolved in 50 mL of deionized water. 0.1 g of CuMnO2 prepared in Example 1 was dispersed in the mixed solution. At room temperature, the mixture was dropped into a 3 wt% CaCl2 solution using a syringe and crosslinked for 1 h. Then, the composite beads were immersed in a 3 w / v glutaraldehyde solution and crosslinked at room temperature for 2 h to obtain CS-Ca@PEI / CuMnO2 composite beads.
[0038] Degradation experiment
[0039] Example 5:
[0040] The degradation of Congo red by three catalytic systems—CuMnO2, PMS, and CS-Ca@PEI / CuMnO2 / PMS—was investigated under pH-unadjusted conditions. First, a certain amount of catalyst (2 g / L) was weighed and added to 50 mL of 100 mg / L CR solution. The pH of the solution was not adjusted. Then, freshly prepared 1 mM PMS was added. Next, the reaction vessel was placed in a constant-temperature shaker at 25 °C and shaken for 90 min. Samples were taken at 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, and 90 min. Immediately after sampling, 100 μL of 0.5 mol / L Na2S2O3 was added to quench the sample, and then the absorbance of the remaining dye in the sample solution was measured.
[0041] Example 6:
[0042] The effect of the catalyst on the degradation performance of CR by activated PMS under different pH conditions: First, the pH of 100 mg / L CR was adjusted using 0.1–5 mol / L HCl and 0.1–5 mol / L NaOH solutions (50 mL each). The pH values were adjusted to 3, 5, 7, 9, and a blank control (Example 5) with no pH adjustment. A certain mass of catalyst (2 g / L) was added, and samples were taken at given time points. Then, 100 μL of 0.5 mol / L Na2S2O3 was immediately added to quench the reaction. Finally, the CR solution in the residual solution was tested. The results showed that the degradation effect of CR was best at pH 7, with a removal rate of 90.97%, indicating that the catalyst has good performance in degrading CR by activated PMS.
Claims
1. A method for preparing cellulose-based composite beads for activating persulfate-degrading dyes, characterized in that, The preparation method is carried out according to the following steps: Step 1: Preparation of CuMnO2: ① Dissolve the copper source in an organic solvent to obtain a copper source solution; dissolve the manganese source in an organic solvent to obtain a manganese source solution; dissolve sodium hydroxide and citrate in deionized water to obtain a sodium hydroxide and citrate solution; ② The copper source solution, manganese source solution, sodium hydroxide and citrate solution are mixed and stirred, then transferred to a reaction vessel. The reaction temperature is 100-200℃ and the reaction time is 10-15h. After the reaction is completed, the reaction product is washed with deionized water and anhydrous ethanol and centrifuged 3-5 times. Then it is dried at 60℃ for 12h to obtain spherical CuMnO2. Step 2: Preparation of CS-Ca@PEI / CuMnO2 composite beads: ① Add cellulose, sodium alginate, polyethyleneimine, and CuMnO2 from step one to deionized water in sequence, and then stir magnetically until homogeneous to obtain the corresponding mixed solution; ② Cellulose, sodium alginate, polyethyleneimine, and CuMnO2 solution from step one are mixed and stirred at a certain temperature for a period of time to form a uniform mixed solution. Beads are obtained by dripping the solution of metal calcium ions into the solution through a syringe. The beads are then separated and immersed in a crosslinking agent solution. After crosslinking for a period of time, they are washed to obtain CS-Ca@PEI / CuMnO2 composite beads.
2. The method for preparing cellulose-based composite beads for activating persulfate-degrading dyes according to claim 1, characterized in that... Step 1① The copper source is one of copper chloride, copper acetate, and copper nitrate; the manganese source is one of manganese chloride, manganese acetate, and manganese nitrate; and the organic solvent is one of polyethylene glycol and polypropylene glycol.
3. The method for preparing cellulose-based composite beads for activating persulfate-degrading dyes according to claim 1, characterized in that... In step 2①, the mass ratio of cellulose, sodium alginate, polyethyleneimine, CuMnO2 and deionized water in step 1 is (0.01~10%):(0.01~10%):(0.02~10%):(0.01~10%):1, and they are stirred at 25~60℃ for 6~12h respectively.
4. The method for preparing cellulose-based composite beads for activating persulfate-degrading dyes according to claim 1, characterized in that... Step 2 ②: Mix the solution and stir at 25-60℃ for 12-24 hours. Then, add it dropwise to the calcium ion crosslinking solution for 1-3 hours. Then, soak it in glutaraldehyde solution at a crosslinking temperature of 25-60℃ for 2-6 hours.
5. The application of the cellulose-based composite beads prepared according to claim 1 for activating persulfate-degrading dyes, wherein CS-Ca@PEI / CuMnO2 composite beads and persulfate are added to wastewater containing reactive dyes, and the persulfate-degrading organic dyes are catalytically activated under natural light conditions, characterized in that... The organic dye is one or a mixture of Congo Red, methyl orange, or Rhodamine B.
6. The application according to claim 5, characterized in that, The amount of CS-Ca@PEI / CuMnO2 composite beads added is 0.5 g / L to 2 g / L, and the amount of persulfate added is 0.5 mM to 2 mM.
7. The application according to claim 5, characterized in that, The concentration of the wastewater containing reactive dyes is 50 mg / L-200 mg / L, and the degradation time is 10 min-90 min.