Effects of engineered nano-titanium dioxide on pore surface properties and phosphorus adsorption of sediment: Its environmental implications

Understanding the environmental safety and human health implications of engineered nanoparticles (ENPs) is of worldwide importance. As an important ENPs, engineered nano-TiO2 (Enano-TiO2) may have been substantially deposited in aquatic sediments because of its widely uses. Sediment pore surface properties would be thus significantly influenced due to the large surface area of Enano-TiO2. In this study, Enano-TiO2 was found to greatly impact on sediment pore surface properties. The attachment of Enano-TiO2 particles to sediment surfaces enhanced markedly BET specific surface area and t-Plot external specific surface area, and thereby increased sediment phosphorus (P) adsorption maximum (S-max). Contrarily, the fill of Enano-TiO2 particles into the micropores of sediments could significantly reduce t-Plot micropore specific surface area, and cause slight decrease in sediment P binding energy (K). Clearly, P sorbed in sediment would be easily released because of the decreasing P binding energy of the sediment with elevated Enano-TiO2. Enano-TiO2 would thus cause aggravated endogenous pollution in water if such sediment was re-suspended on disturbance. The results obtained in this study contribute to our increasing knowledge of how to regulate physicochemical behavior of pollutants in sediments under the influences of Enano-TiO2 and/or similar ENPs. (C) 2011 Elsevier B.V. All rights reserved.