Adsorption Kinetics of Arsenic (V) on Nanoscale Zero-Valent Iron Supported by Activated Carbon

Abstract

The presence of arsenic (As) in drinking water is of serious concern due to its negative impact on human health. This work reports on the kinetics of nanoscale zero-valent iron (Fe0) supported by activated carbon (NZVI/AC) for the removal of As (V) species from aqueous solutions. To better understand the factors affecting this process, we investigated the effects of various experimental parameters including initial As (V) concentration, adsorbent dosage, pH, temperature, and coexisting ions on the adsorption kinetics using a batch-adsorption method. The optimum conditions for As (V) removal by NZVI/AC were found to be: 318 K, pH 3.5, an adsorbent dosage of 1.5 g/L, and an equilibrium time of 72 h. A greater mass of NZVI/AC, lower concentration of As (V) and lower pH positively promoted adsorption kinetics. The presence of phosphate (PO43−) and silicate (SiO42−) markedly inhibited As (V) removal kinetics. However, in the presence of 4.5 g/L NZVI/AC, ≥99.9% of As (V) was removed from raw groundwater.

Removal of Antimony(V) from Drinking Water Using nZVI/AC: Optimization of Batch and Fix Bed Conditions

“…An identical phenomenon was seen in the process of adsorption of acidic dye, [ 41 ], and Cu(II) and Cd(II), Mo(VI) [ 42 , 43 ], upon rice/modified rice husk and activated palm ash on nZVI/BC.…”

Adsorption of Sb(III) from Aqueous Solution by nZVI/AC: A Magnetic Fixed-Bed Column Study

“…In the presence of N 2 bubbling and magnetic stirring, ferrous iron (Fe 2+ ) was reduced by the addition of NaBH 4 . After agitation, the nZVI supported by the AC was separated and washed with acetone before being vacuum dried and stored in an N 2 -purged drying chamber [ 8 , 13 ]. Table 1 summarizes its key characteristics.…”

“…In developing countries, zero-valent iron powders are utilized in permeable reactive barriers to intercept Sb(III) plumes in contaminated groundwater or added to household filters to remove Sb(III) [ 1 ]. Nanoscale zero-valent iron (nZVI) has recently been identified as a promising material for in situ remediations of antimony contaminated water [ 9 , 10 , 11 , 12 , 13 , 14 ]. Due to its high Sb(III) adsorption capability and huge active surface area, it can serve as a viable material to remove Sb(III) from drinking water.…”

“…The batch technique has received greater attention for Sb(III) adsorption. However, adsorption techniques based on the removal of heavy metals carried out in column systems is regarded to be particularly advantageous from an industrial standpoint, due to the column systems’ adaptability to diverse procedures, reduced reagent handling, and consequently low functioning costs [ 10 , 11 , 12 , 13 , 14 ]. As a result, adsorption investigations utilizing columns are required.…”

Nanomaterials and Nanotechnology in Wastewater Treatment

“…In another interesting work [5], authors investigated the CO 2 /CH 4 and He/N 2 separation properties and water permeability valuation of mixed matrix MWCNTsbased cellulose acetate flat sheet membranes in a study about the optimization of the filler material dispersion method. Zhu et al [21] studied the adsorption kinetics of arsenic (V) on nanoscale zero-valent iron supported by activated carbon, while Ramos-Guivar et al [13] focused on the improved removal capacity and equilibrium time of maghemite nanoparticles growth in zeolite type 5A for Pb (II) adsorption. In another "green" nanoadsorption study, Das et al [3] investigated the green synthesis, characterization, and application of natural product coated magnetite nanoparticles for wastewater treatment (the effect of synthesized magnetic nanoparticles in wastewater treatment (bacterial portion), dye adsorption, toxic metal removal, as well as antibacterial, antioxidant, and cytotoxic activities were studied).…”