Tungsten Adsorption on Hematite.

Tungsten (W) is considered an emerging contaminant by USEPA because of its potential impact on public health.  Environmental occurrence of W results from various industrial and domestic applications in tungsten cemented carbides, metal wires, turbine blades, high temperature lubricants, catalysts, incandescent lamp filaments, television sets, and hunting ammunitions.  Many military applications are substituting Lead (Pb) with W.  However, the environmental fate of W is not well known and very complex. Here we propose to study wet chemical and spectroscopic investigations of tungstate and polytungstate adsorption on hematite. Various macroscopic experiments were conducted to understand adsorption capacity of hematite, effect of pH and initial W concentrations on adsorption. To understand the adsorption mechanisms, an in situ ATR-FTIR study at various pH and initial W concentrations were also conducted. The finding from this study can be used to assess the risks of W mobility in iron oxide rich sediments.