Modification of Multilayer Carbon Nanotubes for the Removal of Arsenate

The aim of this study was to explore a new nano-composite carbon adsorbent material for the removal of arsenic from water. The multilayer carbon nanotubes (MCNTs) were treated with different acids and/or modified with iron to create more surface COOH sites or Fe-impregnated MCNTs for the enhanced uptake of As(V). Tests were conducted as a function of initial As(V) concentrations, contact time, and solution pH. The coverage of ferric hydroxides on MCNTs and the uptake of As on Fe-MCNTs were independently confirmed by field emission scanning electron microscope and energy dispersive X-ray spectroscopy analyses. With an As(V) uptake capacities of 27 mg/g on Fe-MCNTs and 14 mg/g on acid-MCNTs, the material showed superior performance for As(V) removal.