Application of titanate nanotubes for ammonium adsorptive removal from aqueous solutions

The potential of adsorptive removal of ammonium with titanate nanotubes (TNT) was investigated. TNT was prepared via a hydrothermal treatment of TiO2 powders in a 10 M NaOH solution at 150 °C for 24 h, and subsequently washed with HCl aqueous solution of different concentrations. Effects of the alteration of microstructures of TNT, induced by the acid washing process, on the ammonium removal performance were discussed. It was experimentally concluded that if the amount of Na+ in the TNT was not very low, TNT might be a good adsorbent for the removal of ammonium from aqueous solution with the adsorption capacity reaching 29 mg/g. The adsorption mechanisms of ammonium from aqueous solution onto TNT were examined with the aid of model analyses of adsorption equilibrium and kinetic data of ammonium.