In view of serious water contamination threats posed by the ever-increasing usage of automobile fuels, the present study explores the potential of a commercially available hydrophobic nano-silica (Aersosil R 812) for the treatment of water contaminated with the gasoline and diesel using the process of adsorption. Owing to its nanometeic dimension, nano-silica Aerosil R 812 offers large surface area (260 m(2)/g) that translates into a higher uptake of gasoline and diesel as compared to other adsorbents reported in the literature with a removal efficiency found to be high as 99% and 97%, respectively, at pH 7. Both kinetic as well as equilibrium studies are carried out here, and the data thus obtained are processed in conjunction with appropriate models to obtain relevant parameters. Moreover, unlike porous-matrix based adsorbents, the nano-silica does not suffer from the pore filling and blockage problem, and therefore shows great promise towards the development of cost-effective water-treatment technology. (c) 2010 Elsevier B.V. All rights reserved.