Adsorption of Cr(VI) from Aqueous Solution by Ethylenediaminetetraacetic Acid-Chitosan-Modified Metal-Organic Framework

2020 ◽  
Vol 20 (3) ◽  
pp. 1660-1669 ◽  
Author(s):  
Yu-Ying Deng ◽  
Xin-Feng Xiao ◽  
Dan Wang ◽  
Bo Han ◽  
Yu Gao ◽  
...  
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Single Molecule ◽  
Ethylenediaminetetraacetic Acid ◽  
Metal Organic Framework ◽  
Concentration Effects ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Metal Organic ◽  
Organic Framework

Cu-BTC was synthesised by hydrothermal method in this study to adsorb and remove the toxic heavy metal hexavalent chromium Cr(VI) in water. The EDTA-chitosan/Cu-BTC was prepared by the surface modification of Cu-BTC with EDTA-modified chitosan. The initial concentration effects of adsorbed chromium solution, adsorbent dosage, adsorption time, adsorption temperature and pH of chromium solution on adsorption capacity were estimated using the single-factor optimisation experiment. Results show that the adsorption capacity of the modified composite was higher than that of Cu-BTC. Cu-BTC and EDTA-chitosan/Cu-BTC exhibited significant adsorption of Cr(VI) under acidic conditions in water and basically independent of temperature. Their adsorption processes conformed with the pseudo-second-order model. The Langmuir adsorption isotherm model obtained the adsorption isotherm, which indicated that the adsorption process was single molecule adsorption. Isotherm fitting obtained the maximum adsorption amounts of Cr(VI) for Cu-BTC and EDTA-chitosan/Cu-BTC at 27.32 and 46.51 mg·g-1, respectively. Factor and principal component analyses show that the main factors affecting the adsorption of Cr(VI) in the EDTA-chitosan/Cu-BTC composites are pH, initial concentration and adsorption time. Therefore, EDTA-chitosan-modified Cu-BTC was a more feasible metal-organic framework material than Cu-BTC because of better adsorption performance, which can be used for adsorption removal of Cr(VI) in water.

scholarly journals Experimental and Modeling of Dicamba Adsorption in Aqueous Medium Using MIL-101(Cr) Metal-Organic Framework

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 419
Author(s):  
Hamza Ahmad Isiyaka ◽  
Khairulazhar Jumbri ◽  
Nonni Soraya Sambudi ◽  
Jun Wei Lim ◽  
Bahruddin Saad ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Adsorption Capacity ◽  
Environmental Concern ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Data Matrix ◽  
Adsorption Parameters ◽  
Metal Organic ◽  
Organic Framework

Drift deposition of emerging and carcinogenic contaminant dicamba (3,6-dichloro-2-methoxy benzoic acid) has become a major health and environmental concern. Effective removal of dicamba in aqueous medium becomes imperative. This study investigates the adsorption of a promising adsorbent, MIL-101(Cr) metal-organic framework (MOF), for the removal of dicamba in aqueous solution. The adsorbent was hydrothermally synthesized and characterized using N2 adsorption-desorption isotherms, Brunauer, Emmett and Teller (BET), powdered X-ray diffraction (XRD), Fourier Transformed Infrared (FTIR) and field emission scanning electron microscopy (FESEM). Adsorption models such as kinetics, isotherms and thermodynamics were studied to understand details of the adsorption process. The significance and optimization of the data matrix, as well as the multivariate interaction of the adsorption parameters, were determined using response surface methodology (RSM). RSM and artificial neural network (ANN) were used to predict the adsorption capacity. In each of the experimental adsorption conditions used, the ANN gave a better prediction with minimal error than the RSM model. The MIL-101(Cr) adsorbent was recycled six times to determine the possibility of reuse. The results show that MIL-101(Cr) is a very promising adsorbent, in particular due to the high surface area (1439 m2 g−1), rapid equilibration (~25 min), high adsorption capacity (237.384 mg g−1) and high removal efficiency of 99.432%.

Highly selective CO2 separation from a CO2/C2H2 mixture using a diamine-appended metal–organic framework

2021 ◽  
Vol 9 (37) ◽  
pp. 21424-21428
Author(s):  
Doo San Choi ◽  
Dae Won Kim ◽  
Dong Won Kang ◽  
Minjung Kang ◽  
Yun Seok Chae ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Metal Organic Framework ◽  
Co2 Separation ◽  
Metal Organic ◽  
Organic Framework

A diamine-appended metal–organic framework displays a top-tier CO2/C2H2 selectivity, a record-high CO2 adsorption capacity, and recyclability.

scholarly journals Synergistic effect of carboxyl and sulfate groups for effective removal of radioactive strontium ion in a Zr-metal-organic framework

2021 ◽  
Author(s):  
Lin Ren ◽  
Xudong Zhao ◽  
Baosheng Liu ◽  
Hongliang Huang
Keyword(s):  
Adsorption Capacity ◽  
High Efficiency ◽  
Metal Organic Framework ◽  
Maximum Adsorption Capacity ◽  
Potential Candidate ◽  
Dual Groups ◽  
Metal Organic ◽  
Strontium Ion ◽  
Rapid Adsorption ◽  
Organic Framework

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.

Towards solvent tuning of slow magnetic relaxation and ferroelectric properties in a dysprosium metal–organic framework system

2019 ◽  
Vol 234 (1) ◽  
pp. 33-41
Author(s):  
Lina Zhang ◽  
Shuyan Guan ◽  
Yunchang Fan ◽  
Chenxia Du ◽  
Dan Zhao ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Molecule ◽  
Magnetic Relaxation ◽  
Metal Organic Framework ◽  
Ferroelectric Properties ◽  
Relaxation Rates ◽  
Slow Magnetic Relaxation ◽  
Metal Organic ◽  
Solvent Molecules ◽  
Organic Framework

Abstract A new dysprosium metal–organic framework {[Dy2(L)3(H2O)4]·(acetone)2·(H2O)3}n (Dy2-Acetone) with single-molecule magnet and ferroelectric properties was synthesized through a solvent-induced single-crystal-to-single-crystal (SCSC) transformation. Notably, exchange of the coordinated and guest solvent molecules lead to different magnetic relaxation and ferroelectric properties in the dysprosium MOF system, Dy2-DMF and Dy2-Acetone. Study reveals that the tunable magnetic relaxation behaviors are most likely a result of different local coordination sphere and lattice solvent molecules within the pores which influenced and tuned the relaxation rates of the magnetization. Moreover, disparate polar solvent molecules confined in the MOFs may be the key factors for their different ferroelectric properties.

A highly porous agw-type metal–organic framework and its CO2 and H2 adsorption capacity

CrystEngComm ◽  
2013 ◽  
Vol 15 (45) ◽  
pp. 9348 ◽  
Author(s):  
Zhiyong Lu ◽  
Liting Du ◽  
Baishu Zheng ◽  
Junfeng Bai ◽  
Mingxing Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Metal Organic Framework ◽  
H2 Adsorption ◽  
Metal Organic ◽  
Highly Porous ◽  
Organic Framework

Synthesis and effect of metal–organic frame works on CO2 adsorption capacity at various pressures: A contemplating review

2019 ◽  
Vol 31 (3) ◽  
pp. 367-388 ◽  
Author(s):  
Ayesha Rehman ◽  
Sarah Farrukh ◽  
Arshad Hussain ◽  
Erum Pervaiz
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Greenhouse Gas Emission ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Climatic Changes ◽  
Microwave Assisted Synthesis ◽  
Synthesis Methods ◽  
Metal Organic ◽  
Organic Framework

The most important environmental challenge that the world is facing today is the control of the quantity of CO2 in the atmosphere, because it causes global warming. Increase in the global temperature results in greenhouse gas emission, interruption of the volcanic activity, and climatic changes. The alarming rise of the CO2 level impels to take some serious action to control these climatic changes. Various techniques are being utilized to capture CO2. However, chemical absorption and adsorption are supposed to be the most suitable techniques for post-combustion CO2 capture, but the main focus is on adsorption. The aim of this study is to provide a brief overview on the CO2 adsorption by a novel class of adsorbents called the metal–organic framework. The metal–organic framework is a porous material having high surface area with high CO2 adsorption capacity. The metal–organic frameworks possess dynamic structure and have large capacity to adsorb CO2 at either low pressure or high pressure due to its cavity size and surface area. Adsorption of CO2 in the metal–organic framework at various pressures depends upon pore volume and heat of adsorption correspondingly. In this review, different synthesis methods of the metal–organic framework such as slow evaporation, solvo thermal, mechanochemical, electrochemical, sonochemical, and microwave-assisted synthesis are briefly described as the structure of the metal–organic frameworks are mostly dependent upon synthesis techniques. In addition to this, different strategies are discussed to increase the CO2 adsorption capacity in the metal organic-framework. [Formula: see text]

Synthesis, characterization and crystal structure of a copper-glutamate metal organic framework (MOF) and its adsorptive removal of ciprofloxacin drug from aqueous solution

2020 ◽  
Vol 44 (10) ◽  
pp. 3961-3969 ◽  
Author(s):  
Margaret D. Olawale ◽  
Adedibu C. Tella ◽  
Joshua A. Obaleye ◽  
Juwon S. Olatunji
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Metal Organic Framework ◽  
Adsorptive Removal ◽  
Metal Organic ◽  
Organic Framework

A novel [Cu(Glu)2(H2O)]·H2O MOF proved to be an effective adsorbent for the removal of ciprofloxacin drug from aqueous solution with an adsorption capacity of 61.35 mg g−1.

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