Preparation method of membrane-encapsulated fiber cloth array oxide micro-reactor and application thereof

Abstract

The application discloses a preparation method of a membrane-encapsulated fiber cloth array oxide micro-reactor and application thereof, and comprises the following steps: (1) nitrate and urea are respectively dissolved in deionized water, the solution is uniformly mixed, and then the pretreated fiber cloth is put into a reaction kettle to react, and after washing and calcination, the fiber cloth array oxide is prepared; (2) an organic polymer and a pore former are dissolved in an organic solvent, stirring and standing are conducted to prepare an encapsulation membrane liquid; and (3) the encapsulation membrane liquid is uniformly poured on the surface of the fiber cloth array oxide, and then immersed in deionized water to perform phase inversion, so that the ultrafiltration catalysis / adsorption micro-reactor is prepared. The micro-reactor has high adsorption and catalysis efficiency for treating sewage, and the removal rate of nitrogen-containing substances, disinfection by-products N-DBPs and precursors reaches about 90%; the micro-reactor has high reactivity, good structural stability, good combination capacity, good anti-interference property and selective adsorption; the material is cheap and easy to obtain, has a wide source, low energy consumption and is easy to industrialize.

Description

Technical Field

[0001] This invention relates to a water treatment device, and more particularly to a method for preparing a membrane-encapsulated fiber array oxide microreactor and its application. Background Technology

[0002] With industrial development, the increasing amount of pollutants generated in industrial production has led to a continuous increase in the types and quantities of disinfectants used in water treatment processes. N-nitrosamine compounds are produced during the chlorination and ozonation processes of water, and these compounds are continuously released into natural aquatic systems, causing serious health problems. Among them, N-nitrosodimethylamine (NDMA) is the most frequently detected N-nitrosamine in drinking water, as it cannot be completely removed. The carcinogenicity and high water mobility of N-nitrosamines have drawn significant attention in water treatment. Adsorption is a common water treatment technology that can remove many micro-pollutants. However, due to the low molecular weight and uncharged nature of N-nitrosamines, conventional adsorbents are difficult to use effectively. Studies have reported that the cyclic coupling of photocatalysis and adsorption processes can effectively remove N-nitrosodimethylamine (NDMA) and N-dimethylaniline (DMA). However, this method has a long reaction time, many interfering factors, and requires segmented treatment of N-nitrosamine pollutants, which greatly increases the treatment cost. Membrane-based reactors can block interference from macromolecular pollutants such as natural organic compounds (NOMs). The micro-reaction interface between membrane materials and nanomaterials can improve mass transfer and rapidly remove pollutants. However, traditional membrane materials have poor selectivity, uneven distribution, poor resistance to macromolecular interference, and cannot accurately control the position of the loaded material, resulting in low removal rates and unstable performance. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a membrane-encapsulated fiber cloth array oxide microreactor with high binding affinity and good removal effect for nitrogen-containing disinfection byproducts N-DBPs and their precursors; another purpose of this invention is to provide applications of this microreactor.

[0004] Technical solution: The preparation method of the membrane-encapsulated fiber cloth array oxide microreactor of the present invention includes the following steps:

[0005] (1) Preparation of fiber cloth array oxide: Nitrate and urea were dissolved in deionized water respectively. After the solution was mixed evenly, it was placed in a reaction vessel with the pretreated fiber cloth and then washed and calcined to obtain fiber cloth array oxide.

[0006] (2) Preparation of encapsulation solution: Dissolve organic polymer and pore-forming agent in organic solvent, stir and let stand to obtain encapsulation solution;

[0007] (3) Preparation of ultrafiltration-catalysis / adsorption microreactor: The encapsulation membrane liquid is uniformly poured onto the surface of the fiber cloth array oxide, and then immersed in deionized water for phase transformation to obtain the ultrafiltration-catalysis / adsorption microreactor UCAM (ultrafiltration-catalysis / adsorption microreactor).

[0008] Furthermore, the fiber cloth pretreatment in step (1) includes calcination at 400-500℃ for 2-3 hours under N2 protection, followed by cutting into 7×7cm pieces. 2 Soak in hydrochloric acid (HCl) or nitric acid (HNO3) for 10-12 hours.

[0009] Furthermore, in step (1), the nitrate is one or more of the following: cobalt nitrate Co(NO3)2·6H2O, nickel nitrate Ni(NO3)2·6H2O, manganese nitrate Mn(NO3)2·6H2O, copper nitrate Cu(NO3)2·6H2O, or ferric nitrate Fe(NO3)3·9H2O.

[0010] Furthermore, in step (2), the mass ratio of organic polymer to porogen is 7.54:0.2-0.03.

[0011] Furthermore, the organic polymer in step (2) is polyvinylidene fluoride (PVDF).

[0012] Furthermore, the pore-forming agent in step (2) is polyvinylpyrrolidone (PVP).

[0013] Furthermore, the organic solvent in step (2) is N,N-dimethylformamide (DMF).

[0014] Furthermore, in step (3), the encapsulation film solution is applied 1-2 times at a uniform speed with a gap of 200-600 nm using a wet film preparation device.

[0015] Furthermore, the fiber cloth is carbon fiber (CC) or cotton fiber (CTC).

[0016] This invention also provides the application of a membrane-encapsulated fiber array oxide microreactor in the removal of nitrogen-containing disinfection byproducts N-DBPs and their precursors from water.

[0017] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: 1. By constructing an ultrafiltration catalytic / adsorption microreactor on an oxide substrate encapsulated with a membrane, adsorption and catalysis work synergistically to rapidly and efficiently remove pollutants from water, achieving a removal rate of approximately 90% for nitrogen-containing disinfection byproducts N-DBPs and their precursors; 2. The micro-reaction interface formed between the membrane substrate of the microreactor and the bimetallic nanoarray improves adsorption and catalytic efficiency, while the bimetallic nanoarray enhances reactivity and structural stability; 3. It exhibits good binding capacity for small molecule amines, histidine, proteins, and other nitrogen-containing disinfection byproducts N-DBPs precursors, enabling effective selective adsorption; 4. It effectively blocks interference from large molecular pollutants such as natural organic matter (NOM), further enhancing the removal effect on nitrogen-containing disinfection byproduct precursors; 5. The fiber cloth material is inexpensive, readily available, and widely sourced. The resulting microreactor reduces the concentration of nitrosamine pollutants in water to drinking water standards, has low energy consumption, is easy to produce industrially, and has excellent application prospects in water treatment processes. Attached Figure Description

[0018] Figure 1 Electron micrographs of Embodiments 1 and 2 of the present invention;

[0019] Figure 2 Microscopic images of the top and bottom surfaces of the UCAM-CC-2 prepared in Example 2 of this invention;

[0020] Figure 3 This is a SEM image of the NiCo2O4 nanoarray of Example 2 of the present invention;

[0021] Figure 4 This is a graph showing the removal rate performance of different metal ratios in this invention;

[0022] Figure 5 The graph shows the PMS removal rate performance of different cobalt-based spinel oxide materials activated by this invention.

[0023] Figure 6 XRD patterns of different metals in this invention;

[0024] Figure 7 XRD patterns of CC, CTC, CoNi-CC / CTC and UCAM-CC / CTC prepared in this invention;

[0025] Figure 8 The image shows the removal rate performance of UCAM-CC / UCAM-CTC, Co-CC, Ni-CC, Co-CTC, Ni-CTC, CC, and CTC prepared according to this invention.

[0026] Figure 9 The anti-interference performance diagram of UCAM-CC-2 prepared in Example 2 of this invention;

[0027] Figure 10 The image shows the reusability performance of the UCAM-CC-2 prepared in Example 2 of this invention. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0029] All reagents used in this invention are of analytical grade. Carbon fiber cloth (CC) and cotton fiber cloth (CTC) were purchased from Carbon Energy Technology Co., Ltd. in Taiwan and Nanjing Garment Factory in China, respectively.

[0030] Pretreatment of the fiber cloth: The purchased carbon fiber cloth (CC) and cotton fiber cloth (CTC) were calcined at 500℃ for 2 hours under N2 protection, and then cut into 7×7cm pieces. 2 Soak in hydrochloric acid (HCl) or nitric acid (HNO3) for 12 hours before use.

[0031] Example 1

[0032] (1) Preparation of fiber cloth array oxide: 1 mol Ni(NO3)2·6H2O, 2 mol Co(NO3)2·6H2O and 0.84 g urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC and reacted at 160℃ for 6 h. After washing with water and ethanol 3 times and calcining at 350℃ for 2 h, fiber cloth array oxide was obtained.

[0033] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.2g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0034] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-1 or UCAM-CTC-1.

[0035] Example 2

[0036] (1) Preparation of fiber cloth array oxide: 1 mol Ni(NO3)2·6H2O, 2 mol Co(NO3)2·6H2O and 0.84 g urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC and reacted at 160℃ for 6 h. After washing with water and ethanol 3 times and calcining at 350℃ for 2 h, fiber cloth array oxide was obtained.

[0037] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0038] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-2 or UCAM-CTC-2.

[0039] Example 3

[0040] (1) Preparation of fiber cloth array oxide: 1 mol of Ni(NO3)2·6H2O, 2 mol of Co(NO3)2·6H2O and 0.84 g of urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC and reacted at 160℃ for 6 h. After washing with water and ethanol three times and calcining at 350℃ for 2 h, fiber cloth array oxide was obtained.

[0041] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.03g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0042] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 mol of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-11 or UCAM-CTC-11.

[0043] Example 4

[0044] (1) Preparation of fiber cloth array oxide: 1 mol Ni(NO3)2·6H2O, 1 mol Co(NO3)2·6H2O and 0.84 g urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC. The reaction was carried out at 160℃ for 6 h. After washing with water and ethanol 3-5 times and calcining at 350℃ for 2 h, the fiber cloth array oxide was obtained.

[0045] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0046] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-3 or UCAM-CTC-3.

[0047] Example 5

[0048] (1) Preparation of fiber cloth array oxide: 2 mol Ni(NO3)2·6H2O, 1 mol Co(NO3)2·6H2O and 0.84 g urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC and reacted at 160℃ for 6 h. After washing with water and ethanol 3 times and calcining at 350℃ for 2 h, fiber cloth array oxide was obtained.

[0049] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0050] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-4 or UCAM-CTC-4.

[0051] Example 6

[0052] (1) Preparation of fiber cloth array oxide: 1 mol Ni(NO3)2·6H2O, 3 mol Co(NO3)2·6H2O and 0.84 g urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC. The reaction was carried out at 160℃ for 6 h. After washing with water and ethanol 3 times and calcining at 350℃ for 2 h, the fiber cloth array oxide was obtained.

[0053] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0054] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-5 or UCAM-CTC-5.

[0055] Example 7

[0056] (1) Preparation of fiber cloth array oxide: 1 mol Ni(NO3)2·6H2O, 4 mol Co(NO3)2·6H2O and 0.84 g urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC. The reaction was carried out at 160℃ for 6 h. After washing with water and ethanol 3 times and calcining at 350℃ for 2 h, the fiber cloth array oxide was obtained.

[0057] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0058] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-6 or UCAM-CTC-6.

[0059] Comparative Example 1

[0060] (1) Preparation of fiber cloth array oxide: 1 mol Cu(NO3)2·6H2O, 2 mol Co(NO3)2·6H2O and 0.84 g urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC. The reaction was carried out at 160℃ for 6 h. After washing with water and ethanol 3 times and calcining at 350℃ for 2 h, the fiber cloth array oxide was obtained.

[0061] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0062] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-7 or UCAM-CTC-7.

[0063] Comparative Example 2

[0064] (1) Preparation of fiber cloth array oxide: 1 mol of Mn(NO3)2·6H2O, 2 mol of Co(NO3)2·6H2O and 0.84 g of urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC and reacted at 160℃ for 6 h. After washing with water and ethanol 3 times and calcining at 350℃ for 2 h, fiber cloth array oxide was obtained.

[0065] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0066] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-8 or UCAM-CTC-8.

[0067] Comparative Example 3

[0068] (1) Preparation of fiber cloth array oxide: 1 mol of Fe(NO3)3·9H2O, 2 mol of Co(NO3)2·6H2O and 0.84 g of urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC and reacted at 160℃ for 6 h. After washing with water and ethanol three times and calcining at 350℃ for 2 h, fiber cloth array oxide was obtained.

[0069] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0070] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-9 or UCAM-CTC-9.

[0071] Comparative Example 4

[0072] (1) Preparation of fiber cloth array oxide: 3 mol of Co(NO3)2·6H2O and 0.84 g of urea were dissolved in deionized water respectively. After the three solutions were mixed evenly, they were placed in a reaction vessel with the pretreated carbon fiber cloth CC or cotton fiber cloth CTC. The reaction was carried out at 150-180℃ for 6-8 h. After washing with water and ethanol 3-5 times and calcining at 350℃ for 2 h, the fiber cloth array oxide was obtained.

[0073] (2) Preparation of encapsulation solution: 7.54g of polyvinylidene fluoride (PVDF) and 0.05g of polyvinylpyrrolidone (PVP) were dissolved in 50ml of N,N-dimethylformamide (DMF), stirred for 12h and allowed to stand for 12h to obtain the encapsulation solution.

[0074] (3) Preparation of ultrafiltration catalytic / adsorption microreactor: 10 ml of encapsulation membrane liquid was uniformly coated once with a wet membrane preparation device at a gap of 500 nm and a speed of 150 mm / s. Then, the encapsulation membrane liquid was uniformly coated once with a gap of 250 nm and a speed of 150 mm / s. The encapsulation membrane liquid was uniformly poured onto the surface of the fiber cloth array oxide and immersed in deionized water for 48 h for phase transformation to obtain ultrafiltration catalytic / adsorption microreactor UCAM-CC-10 or UCAM-CTC-10.

[0075] The UCAM-CC and UCAM-CTC prepared in the above examples and comparative examples were tested as follows:

[0076] 1. Adsorption or catalytic performance of UCAM-CC / CTC for nitrogen-containing disinfection byproducts N-DBPs

[0077] The conventional bottle spot method was used to treat 100 mL of synthesized nitrogen-containing disinfection byproduct N-DBPs solution (pH = 7.5 ± 0.2, pollutant concentration of 0.1 mmol / L) and persulfate PMS solution (concentration of 1 g / L). The nitrogen-containing disinfection byproduct N-DBPs solution was passed through three sequentially connected microreactors at a rate of 4.0 mL / min and the persulfate PMS solution at a rate of 0.4 mL / min. The microreactors were used in a bottom-up mode. The transition metal in the microreactors could effectively activate PMS and enhance its oxidizing power, ultimately achieving synergistic adsorption and catalysis effects, and rapidly and efficiently removing nitrogen-containing disinfection byproduct N-DBPs from wastewater. The results are detailed in Table 1.

[0078] The removal rates of nitrogen-containing disinfection byproducts N-DBPs by experimentally prepared UCAM-CC / UCAM-CTC, Co-CC, Ni-CC, Co-CTC, Ni-CTC, CC, and CTC were evaluated. Figure 8 As shown, CoNi-CC has the highest removal rate, reaching over 80% for all four pollutants.

[0079] Table 1 Removal rate of nitrogen-containing disinfection byproduct N-DBPs

[0080]

[0081] 2. UCAM-CC / CTC Anti-interference Performance Test

[0082] The UCAM-CC-2 prepared in Example 2 was placed at 157 L / m 2 At a high water flux of / h, N-nitrosodimethylamine (NDMA) wastewater containing humic acid (HA) and bovine serum albumin (BSA) was continuously treated. The interference resistance to HA and BSA was tested at intervals, and the results are as follows: Figure 9 As shown.

[0083] 3. Stability testing of UCAM-CC / CTC

[0084] The UCAM-CC-2 prepared in Example 2 was used to treat real industrial wastewater, and the changes in N-nitrosodimethylamine (NDMA) concentration were monitored for 30 consecutive days. The results are as follows: Figure 10 As shown.

[0085] Comparing Examples 1-3, in Example 1, the mass ratio of polyvinylidene fluoride (PVDF) to polyvinylpyrrolidone (PVP) was 7.54:0.2, while in Example 2, the mass ratio of PVP was reduced by a factor of 4 while the PVDF content remained constant. Figure 1 (a) is an electron microscope image of Example 2, and (b) is an electron microscope image of Example 1. Compared with Example 2, the excessively thick membrane coating on the material in Example 1 increases filtration resistance and significantly reduces the adsorption effect on nitrogen-containing disinfection byproducts (N-DBPs), as detailed in Table 1. In Example 3, with a further reduction in polyvinylidene fluoride (PVP), the encapsulation solution cannot be evenly covered on the fiber cloth, resulting in a lower adsorption effect on nitrogen-containing disinfection byproducts (N-DBPs) compared to Examples 1 and 2, as detailed in Table 1. Therefore, a mass ratio of polyvinylidene fluoride (PVDF) to polyvinylidene fluoride (PVP) of 7.54:0.05 was selected for subsequent experiments. Figure 2 Electron microscopy images revealed the microstructure of the top and bottom surfaces of the prepared UCAM, with surface pore sizes of 20-30 nm. Figure 3 The CoNi nanowires shown are uniformly interwoven, completely covering and encapsulating the carbon fiber. (Example:) Figure 9 As shown, at 157 L / m 2 At a high water flux of / h, the UCAM-CC-2 prepared in Example 2 intercepted most of the humic acid (HA) and bovine serum albumin (BSA) at the initial selective separation layer, with an interception rate exceeding 93%. This indicates that UCAM-CC-2 exhibits excellent anti-interference performance in the water remediation of multi-pollutant systems. Comparing the treatment effects of UCAM-CC-2 and ultrafiltration membranes on nitrogen-containing disinfection byproducts (N-DBPs) in Example 2, the synergistic effect of adsorption and catalysis during UCAM-CC-2 treatment reduced the concentration of N-nitrosodimethylamine (NDMA) from approximately 0.217 μg / L to 0.012 ± 0.006 μg / L; conversely, the NDMA content after filtration through ultrafiltration remained at 0.199 ± 0.031 μg / L. Repeated filtration and recycling of real industrial wastewater using the UCAM-CC-2 prepared in Example 2 yielded the following results: Figure 10 As shown, the water flux of UCAM-CC-2 after cleaning was significantly restored and remained almost equal to the initial flux after multiple cycles, mainly due to its excellent self-cleaning performance caused by free radical catalysis. The UCAM-CC-2 prepared in Example 2 showed excellent removal and degradation effects in the long-term treatment of wastewater containing trace amounts of N-nitrosamines, and the performance of the microreactor remained stable after multiple cycles of use.

[0086] Comparative Examples 2-6, the mass ratio of Ni(NO3)2·6H2O to Co(NO3)2·6H2O was changed to investigate the effect of the metal ratio on the performance of CoNi-CC and CoNi-CTC. The XRD patterns of CoNi-CC2-6 and CoNi-CTC2-6 prepared in Examples 2-6 were compared. Figure 6 As shown, in Example 2, the diffraction peaks of Co / Ni=2 are clearly visible at 25.6, 30, 36.1, 36.8, 44.6, 59.2, and 64.9°, indicating that the product has high crystallinity. In contrast, the diffraction peaks of Examples 3-6 at 25.6, 30, or 59.2° have low peak intensities, indicating lower crystallinity. A comparison of the XRD patterns of the experimentally prepared CC, CTC, CoNi-CC / CTC, and UCAM-CC / CTC is shown below. Figure 7 As shown, the similar characteristic peaks of CoNi-CC and CoNi-CTC in Example 2 match those of NiCo2O4 crystal (JCPDS card number: 20-0781), indicating that spinel-type NiCo2O4 grows well on CTC and CC. Meanwhile, peaks related to NiCo2O4 still exist in the spectra of UCAM-CC-2 and UCAM-CTC-2, indicating that NiCo2O4 maintains a crystalline state during the film encapsulation process. Figure 4 The removal rates of N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), and N-nitrosodi-n-propylamine (NDPA) were compared with different metal ratios. It can be seen that the material with the highest removal rate (96%, 86%, 90%, and 94%, respectively) is when Co / Ni = 2, which shows better performance. Therefore, the microreactor prepared with Co / Ni = 2 has the best performance.

[0087] Comparing Example 2 with Comparative Examples 1-4, the effects of varying bimetallic oxide materials on the adsorption / catalytic performance of nitrogen-containing disinfection byproducts were investigated. The degradation of N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), and N-nitrosodi-n-propylamine (NDPA) by PMS activated with five cobalt-based spinel oxide materials was shown in the figure. Figure 5 As shown, NiCo bimetallic materials exhibit the best degradation effect on the aforementioned pollutants. This is because the CoNi nanoarray activates peroxymonosulfate, generating reactive oxygen species that rapidly degrade N-nitrosamines. The breaking of the N-N bond in N-nitrosamines provides an effective binding site for the adsorption of secondary amines, a degradation product. Simultaneously, the electrons conducted by the secondary amine adsorbed on the Ni sites rebuild the charge of the CoNi sites, enhancing the activation effect of peroxymonosulfate and thus removing N-nitrosamines and secondary amines. This synergistic adsorption-catalysis ultimately promotes the removal efficiency of N-nitrosamines; therefore, CoNi bimetallic materials are the optimal choice.

Claims

1. The application of a membrane-encapsulated fiber array oxide microreactor in the removal of nitrogenous disinfection byproducts N-DBPs and their precursors from water, characterized in that, The preparation method of the membrane-encapsulated fiber cloth array oxide microreactor includes the following steps: (1) Preparation of fiber cloth array oxide: Nitrate and urea were dissolved in deionized water respectively. After the solution was mixed evenly, it was placed in a reaction vessel with the pretreated fiber cloth and then washed and calcined to obtain fiber cloth array oxide. (2) Preparation of encapsulation solution: Dissolve organic polymer and pore-forming agent in organic solvent, stir and let stand to obtain encapsulation solution; (3) Preparation of ultrafiltration catalytic / adsorption microreactor: The encapsulation membrane liquid is uniformly poured onto the surface of the fiber cloth array oxide, and then immersed in deionized water for phase transformation to obtain the ultrafiltration catalytic / adsorption microreactor. The oxide in the fiber cloth array oxide obtained in step (1) is NiCo2O4 spinel; In step (2), the porogen is polyvinylpyrrolidone (PVP), and the mass ratio of organic polymer to porogen is 7.54:0.2-0.

03.

2. The application of the membrane-encapsulated fiber array oxide microreactor according to claim 1 in the removal of nitrogenous disinfection byproducts N-DBPs and their precursors of nitrosamines from water, characterized in that, The fiber cloth pretreatment in step (1) includes calcination at 400-500℃ for 2-3 hours under N2 protection, followed by cutting into 7×7 cm pieces. 2 Soak in hydrochloric acid (HCl) or nitric acid (HNO3) for 10-12 hours.

3. The application of the membrane-encapsulated fiber array oxide microreactor according to claim 1 in the removal of nitrogenous disinfection byproducts N-DBPs and their precursors of nitrosamines from water, characterized in that, In step (1), the nitrates are cobalt nitrate Co(NO3)2·6H2O and nickel nitrate Ni(NO3)2·6H2O.

4. The application of the membrane-encapsulated fiber array oxide microreactor according to claim 1 in the removal of nitrogenous disinfection byproducts N-DBPs and their precursors of nitrosamines from water, characterized in that, The organic polymer in step (2) is polyvinylidene fluoride (PVDF).

5. The application of the membrane-encapsulated fiber array oxide microreactor according to claim 1 in the removal of nitrogenous disinfection byproducts N-DBPs and their precursors of nitrosamines from water, characterized in that, The organic solvent in step (2) is N,N-dimethylformamide (DMF).

6. The application of the membrane-encapsulated fiber array oxide microreactor according to claim 1 in the removal of nitrogenous disinfection byproducts N-DBPs and their precursors of nitrosamines from water, characterized in that, In step (3), the encapsulation solution is applied 1-2 times at a uniform speed with a gap of 200-600nm using a wet film preparation device.

7. The application of the membrane-encapsulated fiber array oxide microreactor according to claim 1 in the removal of nitrogenous disinfection byproducts N-DBPs and their precursors of nitrosamines from water, characterized in that, The fiber cloth is either carbon fiber (CC) or cotton fiber (CTC).

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