Arsenic and fluoride removal by iron oxide and iron oxide/alumina nanocomposites

Abstract

The study provides a comparative analysis of As (III), As (V) and F removal by iron oxide nanoparticles and iron oxide/alumina nanocomposites. The nanoparticles were characterized by particle size, zeta potential and Scanning Electron Microscopic analysis which showed spherical iron oxide nanoparticles around ~200 nm and nanocomposites around ~300 nm. Batch sorption studies carried out at varying initial concentrations of As and F revealed an enhanced F and As sorption capacity for the nanocomposites. The sorption isotherm showed that the data for As (III), As (V) and F fitted best to Freundlich isotherm for both the type of nanoparticles. The maximum sorption capacity of the iron oxide nanoparticles for As (III) and As (V) at pH 7 were 909 μg/g and 3333 μg/g while the comparative qm values for the nanocomposites were 1000 μg/g and 2500 μg/g respectively. The maximum F sorption capacity of iron oxide nanoparticles was 1.47 mg/g while it was 4.82 mg/g for the nanocomposites. The preliminary results of the study showed that the nanocomposites can be promising adsorbents for both As and F removal in small scale water systems.