Nano-Structured Magnesium Oxide Coated Iron Ore: Its Application to the Remediation of Wastewater Containing Lead

Magnetically separable nano-structured magnesium oxide coated iron ore (IOMgO) was prepared using environmentally benign chemicals, such as iron ore (10), magnesium(11) nitrate hexahydrate [Mg(NO3)(2)center dot 6H(2)O] and urea; via an easy and fast preparation method. The IOMgO was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and alternating gradient magnetometer (AGM) analyses. The isotherm and kinetic studies indicated that IOMgO has a comparably higher Langmuir constant (K-L, 1.69 L mg(-1)) and maximum sorption capacity (33.9 mg g(-1)) for lead (Pb) than other inorganic media. Based on MgO amount, the removal capacity of Pb by IOMgO was 2,724 mg Pb (g MgO)(-1), which was higher than that (1,980 mg g(-1)) for flowerlike magnesium oxide nanostructures reported by Cao et al. The kinetics, FE-SEM, elemental mapping and XRD results revealed that the substitution followed by precipitation was identified as the mechanism of Pb removal and plumbophyllite (Pb2Si4O10 center dot H2O) was the precipitated phase of Pb. A leaching test revealed that 10mg had negligible concentrations of leached Fe at pH 4-9. Since the base material, IO, is cheap and easily available, IOMgO could be produced in massive amounts and used for remediation of wastewater containing heavy metals, applying simple and fast magnetic separation.