In this work, adsorption of Ni(II) from aqueous solution to titanate nanotubes (TNTs) as a function of various water quality parameters was investigated under ambient conditions. The results indicated that the adsorption of Ni(II) to TNTs was strongly dependent on pH and ionic strength. A positive effect of humic acid (HA)/fulvic acid (FA) on Ni(II) adsorption was found at pH < 6.0, whereas a negative effect was observed at pH > 6.0. At low pH, the adsorption of Ni(II) was dominated by outer-sphere surface complexation or ion exchange with Na+/H+ on TNT surfaces, whereas inner-sphere surface complexation was the main adsorption mechanism at high pH. The TNTs are suitable material for the preconcentration of Ni(II) from large volumes of aqueous solutions. (C) 2010 Elsevier B.V. All rights reserved.