Aggregation of TiO2 Nanoparticles in Aqueous Media: Effects of pH, Ferric Ion and Humic Acid

Introduction As one of the most common nanomaterials, TiO2 nanoparticles have found their industrial and household applications in cosmetics, sunscreens, pharmacy, socks, paints and coatings, catalyst, even food and many other fields, which are expected to continue to grow in the next decade [1]. However, the release of TiO2 nanoparticles into the aquatic environment is inevitable during the process of manufacturing, producing or consuming TiO2 containing products. This draws concerns of potential impact of TiO2 nanoparticles exposure to human and environment, although further investigation is required to understand their potential detailed adverse effects on human beings and the aquatic ecological environment [1,2].