Nanoparticle: A Unique Geochemical Composition in Environment

With at least one dimension less than 100 nm, nanoparticles have been naturally synthesized through biogeochemistry processes in the earth system for billions of years. These nanoparticles have unique properties, and they can participate and thus play distinguished role in various geochemistry processes. From the geochemistry perspective, this paper elaborates the definition and classification of nanoparticles occurring in the environment, emphasizing naturally occurring nanoparticles and incidental nanoparticles in aquatic and weathering crust system, on basis of which nano-minerals are further distinguished from mineral nanoparticles. In addition, origin and formation of nanoparticles in atmosphere and related environmental impact are discussed. In this paper, it also presents current techniques and methods for the characterization and identification of environmental nanoparticles. Furthermore, the geochemistry functions of nanoparticles and their environmental implications are discussed and elucidated, and the frontier issues in this field are summarized.