This work aimed at the development of a novel GO-MoS 2 composite-based adsorbent as an
alternate filter medium for the removal of toxic hexavalent chromium (Cr(VI)) from an
aqueous solution in an up-flow fixed-bed column. The GO-MoS 2 composites were
immobilized over silane-functionalized sand. The synthesized nanocomposites were
validated through FTIR, XRD, SEM, and BET. Subsequently, changes in breakthrough,
saturation time, adsorption capacity, and Cr(VI) removal percentage were evaluated for
various column operating conditions, such as GO-MoS 2 coating percentages, bed heights,
inlet metal concentrations, and flow rates. Results revealed that a maximum uptake capacity
of 556 mg·g -1 was obtained for 0.05% GO-MoS 2 -coated sand, while a maximum removal
efficiency of 56% was attained for 0.1% GO-MoS 2 -coated sand. The adsorption dynamics
were modeled using nonlinear Thomas, Yoon-Nelson, and Adams-Bohart models, which
revealed that Thomas and Yoon-Nelson provided the best data fitting (R 2 = 0.9988). Thomas
model also predicted the adsorption capacities closer to experimental ones. The Bed Depth
Service Time model was also used to scale up the adsorption process for higher throughputs.
Moreover, the Modified Mass Transfer Factor model suggested that mass transfer of Cr(VI)
from bulk solution to the adsorption site on the surface of adsorbent is dependent on porous
diffusion rate at the early breakthroughs. Furthermore, after three regeneration cycles, GO-
MoS 2 -coated sand retained more than 50% regeneration efficiency and a comparatively high
adsorption capacity. Current study indicates potential of novel GO-MoS 2 -coated sand as an
adsorbent for treatment of heavy metals from water.
This work aimed at the development of a novel GO-MoS 2 composite-based adsorbent as an
alternate filter medium for the removal of toxic hexavalent chromium (Cr(VI)) from an
aqueous solution in an up-flow fixed-bed column. The GO-MoS 2 composites were
immobilized over silane-functionalized sand. The synthesized nanocomposites were
validated through FTIR, XRD, SEM, and BET. Subsequently, changes in breakthrough,
saturation time, adsorption capacity, and Cr(VI) removal percentage were evaluated for
various column operating conditions, such as GO-MoS 2 coating percentages, bed heights,
inlet metal concentrations, and flow rates. Results revealed that a maximum uptake capacity
of 556 mg·g -1 was obtained for 0.05% GO-MoS 2 -coated sand, while a maximum removal
efficiency of 56% was attained for 0.1% GO-MoS 2 -coated sand. The adsorption dynamics
were modeled using nonlinear Thomas, Yoon-Nelson, and Adams-Bohart models, which
revealed that Thomas and Yoon-Nelson provided the best data fitting (R 2 = 0.9988). Thomas
model also predicted the adsorption capacities closer to experimental ones. The Bed Depth
Service Time model was also used to scale up the adsorption process for higher throughputs.
Moreover, the Modified Mass Transfer Factor model suggested that mass transfer of Cr(VI)
from bulk solution to the adsorption site on the surface of adsorbent is dependent on porous
diffusion rate at the early breakthroughs. Furthermore, after three regeneration cycles, GO-
MoS 2 -coated sand retained more than 50% regeneration efficiency and a comparatively high
adsorption capacity. Current study indicates potential of novel GO-MoS 2 -coated sand as an
adsorbent for treatment of heavy metals from water.
