Evaluation of Fe-Mg Binary Oxide for As (III) Adsorption-Synthesis, Characterization and Kinetic Modelling

Nanotechnology has received much attention in treating contaminated waters. In the present study, a facile co-precipitation method was employed to synthesize a novel iron and magnesium based binary metal oxide using a stoichiometrically fixed amount of FeNO3 center dot 9H(2)O and MgNO3 center dot 6H(2)O in a proportion of molar concentration 1:1 and was later evaluated in removing As (III) from contaminated waters. Characterization of the prepared nanomaterial was done using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-ray Analysis (EDAX) and ultraviolet-visible spectrophotometry (UV-VIS). Experimental studies on batch scale were carried out, examining the effect of varying initial concentrations of metal, adsorbent dosage, application time and initial pH on removal efficiency. Arsenic removal increased on increasing adsorbent dosage (0.1-1 g/L) but trend reversed on increasing initial arsenic concentration attaining q(max) of 263.20 mg/g. Adsorption was quite efficient in pH range 4-8. Freundlich fitted better for adsorption isotherm along with following Pseudo-2nd order kinetics. The reusability and effect of co-existing ions on arsenic adsorption, namely SO42-, CO32- and PO43- were also explored with reusability in 1st and 2nd cycles attained adsorptive removal up to 77% and 64% respectively. The prepared nano-adsorbent showed promising results in terms of high arsenic uptake (q(max) of 263.20 mg/g) along with facile and cost-effective synthesis. Thus, the co-precipitation technique used in this work is a simple one step procedure without any use of any precursor as compared to most of the other procedures used for synthesis.

Automated summary

In this study, a novel iron and magnesium based binary metal oxide was synthesized using a facile co-precipitation method and evaluated for arsenic removal from contaminated waters. The nano-adsorbent demonstrated high arsenic uptake potential, with efficiency influenced by factors such as adsorbent dosage, initial arsenic concentration, and pH value. The prepared material showed promising results in terms of reusability and its ability to remove arsenic efficiently in a cost-effective manner, making it a viable option for water treatment technologies.