Nanotechnology-based remediation of petroleum impurities from water

Nanotechnology-based methods for removal of oil in petroleum spills and its separation from water are discussed in this review. Oil spills during petroleum extraction and processing and transport are often inavoidable and could lead to events of different impact and magnitude from small contaminations of ground and sea water up to huge disasters. In addition to classic methods of oil removal, the "nano"-techniques are being currently developed, which use nano zero-valent iron (nZVI), carbon nanotubes, sponges, aerogels and nanocomposites, metal and non-metal nanostructurized oxides, nitrides, salts, and zeolites. Some of these nanomaterials can be prepared by "greener" methods at lower costs and without damage to the environment. These methods (except nZVI) are applied presently in small scale due to insufficient knowledge of their toxicity, lack of more detailed investigations or higher costs. Some of these methods are still objects of academic laboratory studies. Simplicity of fabrication, decrease of costs, and commercial availability of applied nanomaterials and their precursors are main objectives of current investigations. (C) 2014 Elsevier B.V. All rights reserved.