(This article is sponsored by The Boston Group)

Challenge

Pollution has long been recognized as a serious threat to both local and global environments and to our quality of life. The development of new technologies that enable industrial economies without harming human health and environments is of critical importance in the 21st century. Development of innovative technologies for manufacturing, transportation, and other activities that reduce or eliminate the production of harmful by-products, or for treatment and remediation of existing toxic substances in the environment, presents major challenges for our society.

Vision

Nanoscale science and engineering can significantly improve our understanding or molecular processes that take place in the environment and help reduce pollution by leading to the development of new \"green\" technologies that minimize the use, production, and transportation of waste products, particularly toxic substances. Environmental remediation will be improved by the removal of contaminants from air and water supplies to levels currently unattainable, and by the continuous and real -time measurements of pollutants. In addition, increasing knowledge of the environmental, social, and human health implications of nanotechnology is critical.

In order to understand the consequences of contaminants moving through the environment, interdisciplinary research is needed on molecular and nanoscale processes that take place at one or more of the interfaces or within nanoscale structures of natural systems. Such research includes studies of inorganic/inorganic, inorganic/organic and organic/inorganic interfaces, with a focus on the specific processes dominated by small length scales. Separation science - exploring the evolving capability to tailor nanostructured membranes - offers new opportunities to selectively extract contaminants from air, water and soil.

Research Example:

Treatment of Contaminated Groundwater with Iron Nanoparticles

Researchers at Lehigh University recently found that nanoscale particles of metallic iron could potentially play a large role in the remediation of contaminated ground water. Interaction between iron and pollutant trichloroethylene (TCE) results in the degradation of TCE to more environmentally benign products. Palladium or platinum is added to the nanoparticles to enhance the rate at which this reaction takes place. The researchers carried out a field demonstration at an industrial site in which nanoparticles injected into groundwater plume containing TCE reduced contaminants levels by up to 96%.

The figures on the right show the schematic depiction of the remediation process in which iron nanoparticles transform a contaminant (trichloroethylene) in water into more environmentally bening products. A wide variety of contaminants (including chlorinated hydrocarbons, pesticides, explosives, polychlorinated biphenyls, and perchlorate) have been successfully broken down in both laboratory and filed tests. The potential for remediation stems from the high reactivity of the nanoparticles and the fact that the technology is portable and highly scalable. The high reactivity of these particles can be attributed to their extraordinarily large surface are (~33.5 m^2/g). With an average particle diameter of less than 100 nanometers, the particles are injectable and can be delivered to contaminant hot spots or source areas as needed.

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