scholarly journals Fabrication of easy separable and reusable MIL-125(Ti)/MIL-53(Fe) binary MOF/CNT/Alginate composite microbeads for tetracycline removal from water bodies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed M. Omer ◽  
Eman M. Abd El-Monaem ◽  
Gehan M. El-Subruiti ◽  
Mona M. Abd El-Latif ◽  
Abdelazeem S. Eltaweil

AbstractIn this investigation, we aimed to fabricate easy separable composite microbeads for efficient adsorption of tetracycline (TC) drug. MIL-125(Ti)/MIL-53(Fe) binary metal organic framework (MOF) was synthetized and incorporated with carbon nanotube (CNT) into alginate (Alg) microbeads to form MIL-125(Ti)/MIL-53(Fe)/CNT@Alg composite microbeads. Various tools including FTIR, XRD, SEM, BET, Zeta potential and XPS were applied to characterize the composite microbeads. It was found that the specific surface area of MIL-125(Ti)/MIL-53(Fe)/CNT@Alg microbeads was 273.77 m2/g. The results revealed that the adsorption of TC augmented with rising CNT proportion up to 15 wt% in the microbeads matrix. In addition, the adsorption process followed the pseudo-second-order and well-fitted to Freundlich and Langmuir models with a maximum adsorption capacity of 294.12 mg/g at 25 ◦C and pH 6. Furthermore, thermodynamic study clarified that the TC adsorption process was endothermic, random and spontaneous. Besides, reusability test signified that MIL-125(Ti)/MIL-53(Fe)/CNT@Alg composite microbeads retained superb adsorption properties for six consecutive cycles, emphasizing its potentiality for removing of pharmaceutical residues.

2021 ◽  
Author(s):  
Ahmed M. Omer ◽  
Eman M. Abd El-Monaem ◽  
Gehan M. El-Subruiti ◽  
Mona M. Abd El-Latif ◽  
Abdelazeem S. Eltaweil

Abstract During the turbulent period of COVID-19, the medical staff is exerting great efforts to preserve humanity. However, the tons of pharmaceutical residues especially antibiotics that is being disposing daily into water bodies may be the seed to an even more ferocious pandemic. Thence, it is inevitable to find out effective strategies for removing these noxious pharmaceutical residues from water. We aimed in this investigation to fabricate easy separable composite microbeads for efficient adsorption of tetracycline (TC) drug. Herein, MIL-125/MIL-53 binary metal organic framework (MOF) was synthetized and incorporated with carbon nanotube (CNT) into alginate (Alg) microbeads to form MIL-125/MIL-53/CNT@Alg composite microbeads. Various tools including FTIR, XRD, SEM, BET, Zeta potential and XPS were applied to characterize the composite microbeads. The results revealed that the adsorption of TC was augmented with rising TC proportion up to 15 wt% in the microbeads matrix. In addition, the adsorption process followed the pseudo-second-order and well-fitted to Freundlich and Langmuir models with a maximum adsorption capacity of 294.12 mg/g at 25 ◦C, while the adsorption process was endothermic, randomness and spontaneous. Besides, reusability test signified that MIL-125/MIL-53/CNT@Alg composite microbeads retained admirable adsorption properties for six consecutive cycles, emphasizing its potentiality for removing of pharmaceutical residues.


2013 ◽  
Vol 395-396 ◽  
pp. 637-640
Author(s):  
Yi Yang ◽  
Zheng Ping Wang ◽  
Ling Meng ◽  
Lian Jun Wang

MIL-101, a metal-organic framework material, was synthesized by the high-temperature hydrothermal method. Triethylenetetramine (TETA) modification enabled the effective grafting of an amino group onto the surface of the materials and their pore structure. The crystal structure, micromorphology, specific surface area, and pore structure of the samples before and after modification were analyzed with an X-ray diffractometer, scanning electron microscope, specific surface and aperture tester, and infrared spectrometer. The carbon dioxide adsorption properties of the samples were determined by a thermal analyzer before and after TETA modification. Results show that moderate amino modification can effectively improve the microporous structure of MIL-101 and its carbon dioxide adsorption properties. After modification, the capacity of MIL-101 to adsorb carbon dioxide decreased only by 0.61 wt%, and a high adsorption capacity of 9.45 wt% was maintained after six cycles of adsorption testing at room temperature and ambient pressure.


2009 ◽  
Vol 11 (18) ◽  
pp. 3515 ◽  
Author(s):  
Vincent Finsy ◽  
Sofia Calero ◽  
Elena García-Pérez ◽  
Patrick J. Merkling ◽  
Gill Vedts ◽  
...  

Author(s):  
Lin Ren ◽  
Xudong Zhao ◽  
Baosheng Liu ◽  
Hongliang Huang

Abstract Rapid removal of radioactive strontium from nuclear wastewater is of great significance for environment safety and human health. This work reported the effective adsorption of strontium ion in a stable dual-group metal-organic framework, Zr6(OH)14(BDC-(COOH)2)4(SO4)0.75 (Zr-BDC-COOH-SO4), which contains strontium-chelating groups (-COOH and SO4) and strongly ionizable group (-COOH). Zr-BDC-COOH-SO4 exhibits very rapid adsorption kinetics (<5 min) and a maximum adsorption capacity of 67.5 mg g−1. The adsorption behaviors can be well evaluated by pseudo-second-order model and Langmuir isotherm model. Further investigations indicate that the adsorption of Sr2+ in Zr-BDC-COOH-SO4 would not be interfered by solution pH and adsorption temperature obviously. Feasible regeneration of the adsorbent was also demonstrated through a simple elution method. Mechanism investigation suggests that free -COOH contributes to the rapid adsorption based on electrostatic interaction while introduction of -SO4 can enhance the adsorption capacity largely. Thus, these results suggest that Zr-BDC-COOH-SO4 might be a potential candidate for Sr2+ removal and introducing dual groups is an effective strategy for designing high-efficiency adsorbents.


2019 ◽  
Author(s):  
Jonathan Carney ◽  
David Roundy ◽  
Cory M. Simon

Metal-organic frameworks (MOFs) are modular and adjustable nano-porous materials with applications in gas storage, separations, and sensing. Flexible/dynamic components that respond to adsorbed gas can give MOFs unique or enhanced adsorption properties. Here, we explore the adsorption properties that could be imparted to a MOF by a rotaxane molecular shuttle (RMS) in its pores. In an RMS-MOF, a macrocyclic wheel is mechanically interlocked with a strut. The wheel shuttles between stations on the strut that are also gas adsorption sites. We pose and analyze a simple statistical thermodynamic model of gas adsorption in an RMS-MOF that accounts for (i) wheel/gas competition for sites on the strut and (ii) the entropy endowed by the shuttling wheel. We determine how the amount of gas adsorbed, position of the wheel, and energy change upon adsorption depend on temperature, pressure, and the interactions of the gas/wheel with the stations. Our model reveals that, compared to an ordinary Langmuir material, the chemistry of the RMS-MOF can be tuned to render adsorption more or less temperature-sensitive and release more or less heat upon adsorption. The model also uncovers a non-monotonic relationship between temperature and the position of the wheel if gas out-competes the wheel for its preferable station.


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