Nano-Porous Composites of Activated Carbon–Metal Organic Frameworks (Fe-BDC@AC) for Rapid Removal of Cr (VI): Synthesis, Adsorption, Mechanism, and Kinetics Studies

Abstract

Metal–organic frameworks (MOFs) are a group of porous materials that display potential in the elimination of toxic industrial compounds (TICs) from polluted water streams. However, their applications have so far been held up by issues due to their physical nature and cost. In this study, activated carbon (AC) is modified with an Fe-based MOF, iron terephthalate (Fe-BDC). A facile and cost-effective impregnation method is used for enhanced removal from aqueous solutions. The new adsorbent is characterized by SEM, FTIR, PXRD, and BET. The composite displays excellent uptake of Cr (VI) when compared to un-impregnated AC with a maximum monolayer adsorption capacity of 100 mg·g−1. The experimental data shows a high correlation to the Langmuir adsorption model. The adsorption kinetic study reveals that the adsorption of Cr (VI) to Fe-BDC@AC obeys the pseudo-first-order equation. The composite shows high reusability after five cycles and high adsorption rates reaching equilibrium in just 50 min. Such properties make the nanocomposite promising for water decontamination on larger scales compared to powder-based alternatives, such as individual MOF crystals.

Investigation of the Adsorption Process of Chromium (VI) Ions from Petrochemical Wastewater Using Nanomagnetic Carbon Materials

“…The electrostatic attraction could be helpful for Cr(VI) ions were adsorbed on the surface of this adsorbent at acidic solution. A similar trend is reported on Cr(VI) ions on Fe-BDC@AC [ 59 ].…”

Designing of Zn (II)‐based novel coordination polymer (CP): Synthesis, characterization, and heavy metal removal from water

“…As shown, the removal efficiency slowly decreased with higher numbers of regeneration cycles. The decrease in removal efficiency may be attributed to loss of adsorption sites on the surfaces by multiple adsorption–desorption experiments [18, 50, 51]. Although the removal efficiency was reduced, it was sustained at a level of 77% for the fifth cycle.…”

Current trends in the synthesis, characterization and application of metal-organic frameworks

“…The adsorption kinetic study reveals that the adsorption of Cr( vi ) onto Fe-BDC@AC obeys the pseudo-first-order equation indicating that the nanocomposite is promising for water decontamination. 153 The fundamental principles that govern all the adsorption cases are similar and linked to the inherent properties of the MOFs which include a large surface area and tunable pore sizes and due to interactions of electrostatic nature.…”