Nanotechnology and the environment

This chapter presents different phenomena that arise when nanomaterials reach the environment, with emphasis in water systems. Transformations on the surface of nanomaterials and nanoparticles because of adsorption of macromolecules and metals cations, as well as biological interactions alter their colloidal stability, originating in some cases homoaggregation or heteroaggregation, which in turn affects their fate and transport. Some engineering applications of nanomaterials are highlighted: as adsorbents, as enhancers of water filtration, providing antifouling, catalytic, and antibacterial activity, and as catalysts, giving special attention to photoactivity and to the removal of indoor air contaminants as volatile organic compounds.