Removal of mercury(II) from contaminated water by gold-functionalised FeO magnetic nanoparticles.

FeO nanoparticles were prepared by co-precipitation of Fe and Fe and then modified with Au to produce an effective adsorbent (FeO/Au) for aqueous Hg(II) in contaminated water. Rietveld refinement on the XRD pattern confirmed that the FeO/Au was synthesised. Mössbauer spectra exhibited broad and asymmetric resonance lines with two sextets which can be assigned to tetrahedral Fe; and octahedral Fe/Fe. The quantitative analysis of magnetite confirms that the sample shows around 3 wt.% Au and 97 wt.% partially oxidised FeO. High surface area: 121 m g, average pore sizes: 6.3 nm and pore volume: 1.64 cm g. The kinetics data were better fitted with a pseudo-second-order and Dubinin-Radushkevich isotherm suggests the Hg(II) adsorption onto FeO/Au nanoparticles was mainly by chemical adsorption forming complex with the Au metal immobilised on FeO surfaces. Adsorption capacity of 79.59 mg g. Ionic strength and co-existing ions had a slight influence on the adsorption capacity.