Application of Fe-CN adsorbent material in adsorption of bisphenol A in water

Abstract

The invention discloses an application of a Fe-CN adsorbent material in adsorbing bisphenol A in water, which comprises the following steps: adding the Fe-CN adsorbent material into water containing bisphenol A, and adsorbing the bisphenol A in the water, the preparation method of the Fe-CN adsorbent material comprises the following steps: (1) calcining urea at 500-600 DEG C to obtain a carbon-nitrogen material; and (2) uniformly dispersing the carbon-nitrogen material and ferrous oxalate in water, drying, and calcining in an inert atmosphere at 500-600 DEG C to obtain the Fe-CN adsorbent material. The Fe-CN adsorbent material disclosed by the invention has extremely high adsorption performance on bisphenol A.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to application of an Fe-CN adsorbent material in adsorbing bisphenol A in water. Background Art

[0002] At present, with the rapid development of society, a large amount of industrial wastewater and domestic sewage has been generated, and these sewage cannot be cleared in time, causing great damage to our ecological environment.

[0003] Bisphenol (BPA) is an industrial compound widely used in the production of plastics and resins. It is commonly found in everyday items such as food packaging, baby bottles, and thermal paper (such as shopping receipts). Its chemical structure is similar to that of estrogen, and it can cause multiple health hazards to humans through endocrine disruption, including reproductive and developmental toxicity, associations with chronic diseases, carcinogenicity, cardiovascular disease, neurological abnormalities, and decreased immunity. Infants, young children, and pregnant women are particularly susceptible.

[0004] BPA concentrations in the environment are low and widely distributed, making it a long-standing source of contamination. Currently, methods for removing BPA from aquatic environments include biological methods, chemical oxidation methods, and adsorption methods. Biological methods offer advantages for treating BPA due to their long duration and wide range of action. However, these methods also have challenges such as long microbial strain acclimation times, demanding operating conditions, prolonged pollutant degradation time, difficulty in mineralizing pollutants, potential for secondary pollution, and high economic costs. Chemical oxidation methods remove BPA by chemically disrupting BPA's structure, leading to degradation or mineralization. However, degradation intermediates can lead to secondary pollution.

[0005] Adsorption is the key to removing BPA from water. Chinese patent publication CN 105107465A discloses an adsorbent for absorbing bisphenol A from water. This adsorbent is a hexadecyl-N-ethylimidazole double-bonded silica gel, with an adsorption capacity of no more than 40 mg / g of bisphenol A. Chinese patent publication CN 106861658A discloses a highly efficient porous adsorbent modified with polyethyleneimine, capable of absorbing approximately 24 mg of bisphenol A per gram of bisphenol A.

[0006] The adsorption capacity of bisphenol A by existing adsorbents is limited. Summary of the Invention

[0007] The present invention provides an application of an Fe-CN adsorbent material in adsorbing bisphenol A in water. The Fe-CN adsorbent material has extremely high adsorption performance for bisphenol A.

[0008] The technical solutions of the present invention are as follows: An application of an Fe-CN adsorbent material in adsorbing bisphenol A in water comprises: adding the Fe-CN adsorbent material to water containing bisphenol A to adsorb the bisphenol A in the water; The preparation method of the Fe-CN adsorbent material comprises: (1) calcining urea at 500-600°C to obtain carbon-nitrogen material; (2) The carbon-nitrogen material and ferrous oxalate are uniformly dispersed in water, dried, and then calcined at 500-600°C under an inert atmosphere to obtain a Fe-CN adsorbent material.

[0009] The Fe-CN adsorbent material of the present invention exhibits excellent adsorption and degradation performance for bisphenol A. This performance is attributed to the fact that Fe doping optimizes the electronic structure of the carbon-nitrogen material, forming a Z-type heterojunction that promotes photogenerated carrier separation and enhances the adsorption capacity for bisphenol A through the Fe active sites. The precursors of the carbon-nitrogen material and the Fe precursor have a crucial influence on the adsorption performance of the final adsorbent material. Furthermore, the specific surface area of ​​Fe-CN enhances its surface hydroxyl radical generation capacity (e.g., the Fenton effect), which can synergistically degrade BPA.

[0010] The carbon-nitrogen material is g-C3N4.

[0011] Preferably, in step (1), the urea is calcined for 1-5 hours, and then ground after cooling to obtain a carbon-nitrogen material.

[0012] Preferably, the molar ratio of the carbon-nitrogen material to the ferrous oxalate is 1-5:1.

[0013] More preferably, the molar ratio of the carbon-nitrogen material to ferrous oxalate is 1-1.5: 1. Under this molar ratio, Fe-N and Fe-C can be well generated while iron is also present.

[0014] Preferably, in step (2), calcining at 500-600°C under an inert atmosphere comprises: heating to 500-600°C at a rate of 1-5°C / min under an inert atmosphere, and calcining at 500-600°C for 1-5h.

[0015] Preferably, the X-ray diffraction pattern of the Fe-CN adsorbent material has diffraction peaks at 2θ of 37.6°, 39.7°, 40.6°, 42.8°, 43.6°, 44.5°, 44.8°, 44.9°, 45.8°, 48.5°, 49.1°, 51.8°, 54.3°, and 57.9°.

[0016] Preferably, the main components of the Fe-CN adsorbent material are Fe3C, Fe3N and Fe.

[0017] The Fe-CN adsorbent material structure is a nano-scale particle agglomeration structure.

[0018] Preferably, the concentration of bisphenol A in the water containing bisphenol A is 1-500 mg / L.

[0019] Preferably, based on the volume of water containing bisphenol A, the dosage of the Fe-CN adsorbent material is 0.1-10 g / L; and the adsorption time is 0.1-5 h.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The invention adopts a specific carbon-nitrogen precursor and an Fe precursor to prepare a specific Fe-CN adsorbent material, and the Fe-CN adsorbent material has excellent adsorption performance for bisphenol A in water.

[0021] The raw materials for preparing the Fe-CN adsorbent material of the present invention are low-cost, no precious metals or complex equipment are required, and the preparation method is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the XRD spectrum of the adsorbent prepared in Example 1.

[0023] Figure 2 These are scanning electron microscope photos of the adsorbent prepared in Example 1, where the scale bar in (a) is 200 nm and the scale bar in (b) is 1 μm.

[0024] Figure 3 This is a graph showing the adsorption performance of bisphenol A by the adsorbents prepared in Examples 1-3 and Comparative Examples 1-2 under the same conditions.

[0025] Figure 4 This is a graph showing the adsorption performance of bisphenol A by the adsorbents prepared in Example 1 and Comparative Examples 3-5 under the same conditions. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be noted that the following examples are intended to facilitate understanding of the present invention and do not have any limiting effect on the present invention.

[0027] Example 1 10 g of urea was placed in a crucible, kept at 550 °C in a muffle furnace for 2 h, and then ground after natural cooling to obtain light yellow powdery g-C3N4.

[0028] 0.894 mmol of ferrous oxalate (FeC2O4•2H2O) and 3.704 mmol of g-C3N4 were uniformly dispersed in 10 mL of deionized water and stirred at 600 rpm on a magnetic stirrer for 2 hours. The solution was poured onto a watch glass and dried in an oven at 60°C. The dried sample was removed and ground into a powder in a mortar. The powder was placed in a covered porcelain boat and calcined at 550°C for 2 hours in a tube furnace under nitrogen to obtain the adsorbent, labeled FeC2O4-CN-550 (urea).

[0029] Example 2-3 10 g of urea was placed in a crucible, kept at 550 °C in a muffle furnace for 2 h, and then ground after natural cooling to obtain light yellow powdery g-C3N4.

[0030] 0.894 mmol of ferrous oxalate (FeC2O4•2H2O) and 3.704 mmol of g-C3N4 were uniformly dispersed in 10 mL of deionized water and stirred at 600 rpm on a magnetic stirrer for 2 hours. The liquid was poured onto a watch glass and dried in an oven at 60°C. The dried sample was removed and ground into a powder using a mortar. The powder was placed in a covered porcelain boat and calcined in a tube furnace under nitrogen at 500°C (Example 2) and 600°C (Example 3) for 2 hours to obtain adsorbents, labeled FeC2O4-CN-500 (urea) and FeC2O4-CN-600 (urea), respectively.

[0031] Comparative Example 1-2 10 g of urea was placed in a crucible, kept at 550 °C in a muffle furnace for 2 h, and then ground after natural cooling to obtain powdered g-C3N4.

[0032] 0.894 mmol of ferrous oxalate (FeC2O4•2H2O) and 3.704 mmol of g-C3N4 were uniformly dispersed in 10 mL of deionized water and stirred at 600 rpm on a magnetic stirrer for 2 hours. The liquid was poured onto a watch glass and dried in an oven at 60°C. The dried sample was removed and ground into a powder in a mortar. The powder was then calcined in a tube furnace under nitrogen at 400°C (Comparative Example 1) and 450°C (Comparative Example 2) for 2 hours to obtain adsorbents, labeled FeC2O4-CN-400 (urea) and FeC2O4-CN-450 (urea), respectively.

[0033] Comparative Example 3 10 g of melamine was placed in a crucible, kept at 550 °C for 2 h, naturally cooled and then ground to obtain dark yellow powdery g-C3N4.

[0034] 0.894 mmol of ferrous oxalate (FeC2O4•2H2O) and 0.1 g of CN were evenly dispersed in 10 mL of deionized water and stirred at 600 rpm on a magnetic stirrer for 2 hours. The liquid was poured onto a watch glass and dried in an oven at 60°C. The dried sample was removed and ground into a powder using a mortar. The powder was then calcined in a tube furnace at 550°C for 2 hours under nitrogen to obtain the adsorbent, labeled FeC2O4-CN (melamine).

[0035] Comparative Example 4 10 g of urea was placed in a crucible, kept at 550 °C for 3 h, naturally cooled and then ground to obtain powdered g-C3N4.

[0036] Disperse 0.894 mmol of anhydrous ferrous sulfate (FeSO₄) and 0.1 g of CN in 10 mL of deionized water. Stir the mixture at 600 rpm on a magnetic stirrer for 2 hours. Pour the mixture onto a watch glass and dry it in an oven at 60°C. Grind the dried sample into a powder in a mortar and pestle. Calcin the powder in a tube furnace at 550°C for 2 hours under nitrogen to obtain the adsorbent, labeled FeSO₄-CN.

[0037] Comparative Example 5 10 g of urea was placed in a crucible, kept at 550 °C for 3 h, naturally cooled and then ground to obtain powdered g-C3N4.

[0038] Disperse 0.894 mmol of ferric nitrate nonahydrate (Fe(NO₃)₃·9H₂O) and 0.1 g of CN in 10 mL of deionized water. Stir the mixture at 600 rpm on a magnetic stirrer for 2 hours. Pour the mixture onto a watch glass and dry it in an oven at 60°C. Grind the dried sample into a powder in a mortar and pestle. Calcin the powder in a tube furnace at 550°C for 2 hours under nitrogen to obtain the adsorbent, labeled Fe(NO₃)₃-CN.

[0039] The adsorbent material prepared in Example 1 was characterized using a Smartlab SE intelligent multifunctional X-ray diffractometer from Rigaku, Japan. The test conditions were as follows: target source Cu, scanning speed of 2° / min, and scanning angle of 5-90°.

[0040] The surface morphology (SEM) was measured by a German ZEISS Sigma 300 scanning electron microscope. The accelerating voltage was 3 kV when the morphology was photographed. The sample preparation method was to place the sample directly on the conductive glue, and the test mode was secondary electron.

[0041] Figure 1This is the X-ray diffraction pattern of the adsorbent material FeC2O4-CN-550 (urea) prepared in Example 1. As can be seen from the figure, the peaks of FeC2O4-CN-550 (urea) are obvious and sharp, indicating that the material has good crystallinity. The diffraction peaks at 2θ=37.6°, 39.7°, 40.6°, 42.8°, 44.5°, 44.9°, 45.8°, 48.5°, 49.1°, 51.8°, 54.3° and 57.9° can be attributed to the characteristic peaks of Fe3C (JCPDS no.85-1317). The diffraction peaks at 2θ=43.6° and 44.8° can be attributed to FeN 0.0560 (JCPDS no.75-2137). The diffraction peak at 2θ=44.5 can be attributed to the characteristic peak of Fe (JCPDS no.06-0696). It can be seen that FeC2O4-CN-550 (urea) is mainly composed of Fe3C, FeN 0.0560 and Fe.

[0042] Figure 2 This is a scanning electron micrograph of the adsorbent material FeC2O4-CN-550 (urea) prepared in Example 1. It shows a structure of aggregated nanoparticles. The nanoparticles themselves have a large specific surface area and a rough surface, but even after agglomeration, they retain a large number of pores, significantly improving their adsorption performance.

[0043] Application Example 1 Experiments for adsorbing bisphenol A (BPA) in simulated wastewater were conducted in 500ml beakers at room temperature and pressure. All solutions were prepared with deionized water. The initial pH of the solutions was 7.0, the BPA concentration was 0.05g / L, and the adsorbent dosage was 100ml. The adsorbent dosage was 0.3g / L. The BPA content in the solution was determined using a high-performance liquid chromatograph (Ultimate 3000HPLC-Q) equipped with a C18 column. This application example primarily investigated the adsorption performance of the adsorbents prepared in Examples 1-3 and Comparative Examples 1-5 for BPA within 30 minutes under the same conditions. The results are shown in Figure 2. Figure 3 and Figure 4 shown.

[0044] The adsorbent FeC2O4-CN-550 (urea) prepared in Example 1 has excellent adsorption performance for bisphenol A, and the adsorption capacity for bisphenol A is 107 mg / g.

[0045] Depend on Figure 3It can be seen that compared with comparative examples 1-2, the adsorption performance of the adsorbents prepared in Examples 1-3 is greatly improved, among which FeC2O4-CN-550 (urea) prepared in Example 1 has the best adsorption performance for bisphenol A, and the adsorption rate of bisphenol A reaches about 64% within 30 minutes.

[0046] Depend on Figure 4 It can be seen that compared with comparative examples 3-5, the adsorption performance of the adsorbent FeC2O4-CN-550 (urea) prepared in Example 1 is greatly improved, and the adsorption rate of bisphenol A reaches about 64% within 30 minutes.

[0047] The adsorbent of this invention is primarily composed of nitrogen-rich precursor urea and inexpensive iron salts. It can be synthesized through a simple process involving water dissolution and calcination, requiring no precious metals or complex equipment. Its high efficiency stems from the fact that Fe doping optimizes the electronic structure of g-C3N4, forming a Z-type heterojunction that promotes photogenerated carrier separation and enhances pollutant adsorption through Fe active sites. The g-C3N4 and Fe precursors have a crucial influence on the adsorption properties of the final adsorbent. Furthermore, the increased specific surface area and surface hydroxyl radical generation capacity of Fe-CN (e.g., the Fenton effect) synergistically degrade BPA. Experimental results show that the FeC2O4-CN-550 (urea) prepared in this invention exhibits an adsorption rate exceeding 60% for 50 ppm BPA, and a maximum adsorption capacity of 107 mg / g for 50 ppm bisphenol A. These low-cost and high-activity properties make it highly promising for environmental remediation applications. The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Application of an Fe-CN adsorbent material in adsorbing bisphenol A in water, characterized in that: include: adding the Fe-CN adsorbent material into water containing bisphenol A to adsorb the bisphenol A in the water; The preparation method of the Fe-CN adsorbent material comprises: (1) calcining urea at 500-600°C to obtain carbon-nitrogen material; (2) The carbon-nitrogen material and ferrous oxalate are uniformly dispersed in water, dried, and then calcined at 500-600°C under an inert atmosphere to obtain a Fe-CN adsorbent material.

2. Use of the Fe-CN adsorbent material according to claim 1 in adsorbing bisphenol A in water, characterized in that: In step (1), the urea is calcined for 1-5 hours, and then ground after cooling to obtain a carbon-nitrogen material.

3. Use of the Fe-CN adsorbent material according to claim 1 in adsorbing bisphenol A in water, characterized in that: The molar ratio of the carbon-nitrogen material to the ferrous oxalate is 1-5:

1.

4. Use of the Fe-CN adsorbent material according to claim 1 in adsorbing bisphenol A in water, characterized in that: In step (2), calcining at 500-600°C under an inert atmosphere comprises: heating to 500-600°C at a rate of 1-5°C / min under an inert atmosphere, and calcining at 500-600°C for 1-5h.

5. Use of the Fe-CN adsorbent material according to claim 1 in adsorbing bisphenol A in water, characterized in that: The X-ray diffraction pattern of the Fe-CN adsorbent material has diffraction peaks at 2θ of 37.6°, 39.7°, 40.6°, 42.8°, 43.6°, 44.5°, 44.8°, 44.9°, 45.8°, 48.5°, 49.1°, 51.8°, 54.3°, and 57.9°.

6. Use of the Fe-CN adsorbent material according to claim 1 or 5 in adsorbing bisphenol A in water, characterized in that: The main components of the Fe-CN adsorbent material are Fe3C, FeN 0.0560 and Fe.

7. Use of the Fe-CN adsorbent material according to claim 1 in adsorbing bisphenol A in water, characterized in that: The concentration of bisphenol A in water is 1-500 mg / L.

8. Use of the Fe-CN adsorbent material according to claim 1 in adsorbing bisphenol A in water, characterized in that: Based on the volume of water containing bisphenol A, the dosage of the Fe-CN adsorbent material is 0.1-10 g / L; and the adsorption time is 0.1-5 hours.

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