Using Nanotechnology to Detect, Clean Up and Prevent Environmental Pollution
Nanotechnology is being explored for its potential to provide new solutions to managing and cleaning up pollution in our air, water and land, and improving the performance of conventional technologies used in cleanup efforts.
The unique properties and characteristics of nanomaterials also lend themselves to being used to prevent pollution by reducing the release or emission of industrial hazardous waste and other pollutants.
Research is needed to develop pollution control technologies and determine the application of nanotechnology to reduce waste during manufacturing processes or to enhance manufacturing efficiencies so that pollution is prevented. For example, nanomaterials from natural bioproducts (such as plant extracts) may replace some petroleum-based materials, thus reducing the pollution that occurs in the production and disposal of these products.
EPA's nanotechnology research is playing a significant role in advancing the development and implementation of nanotechnologies to improve treatment, management and prevention of pollution.
Scientific questions being addressed in this area of research include:
- How can nanomaterials be applied in a sustainable manner for treatment and remediation of contaminants?
- How can nanomaterials be used to minimize waste through the substitution of less-toxic chemical components or through enhanced efficiencies in manufacturing?
Initial efforts are focused on key pollutants of concern to EPA that historically have been difficult to manage such as sources that emit low concentrations of air pollutants and hazardous materials in complex cleanup sites.
Research is also focused on learning more about which nanomaterials have enhanced catalytic properties, meaning they can be used to speed up or slow down the rate of a chemical reaction. These catalytic materials are being studied to determine their use in various environmental applications, including the reduction of air pollution.
Researchers are also:
Examining the potential of some inorganic nanoscale materials to remove metals and organic contaminants from air and water effluents generated as a result of manufacturing and power-generation operations.
Studying the use of nanoscale iron particles to remediate industrial waste contaminated with pesticides, PCBs, heavy metals, and chemicals such as arsenates, perchlorates, and nitrates.
Investigating the ability to physically and chemically tailor substances, surfaces, and pores at the nano-scale to improve selectivity and efficiency of membrane filtration, adsorption, and catalysis. The objective is to identify and evaluate innovative, high-performance or lower-cost alternatives for treating critical contaminants.
Developing nanoscale metallic solids or biopolymers for the destruction of organic contaminants or the extraction of inorganic contaminants from ground water and soil.
Application and Impact:
New methods, models, and tools are being generated by EPA’s nanotechnology research to remediate or prevent the amount of pollution that enters the environment.
A study using novel nanoparticles to improve efforts to clean up sites contaminated by polychlorinated biphenyls (PCBs) and similar compounds has shown promising results. Researchers synthesized activated carbon, traditionally used to absorb contaminants, with a nanoparticle iron/palladium bimetallic. This made the activated carbon not only more effective in trapping and isolating the PCBs in sediments but also degraded the contaminants to less harmful and biodegradable compounds.
The findings are leading to the development of innovative practices to develop caps or barriers to contain and degrade PCBs. In 2008, a paper describing the research, published in Environmental Science and Technology, received an award based on its impact.
A study also found emulsified nano iron particles can be injected into soil to treat groundwater contaminated by the dry cleaning solvent, tetrachloroethene (PCE) and its sister products.
Preliminary results indicate the nanomaterial is effective at absorbing contaminants and transforming them into nontoxic forms. The findings have implications for nanotechnology treatment of other contaminants in groundwater, although additional research will be needed.
Hyeok Choi, Shirish Agarwal, Souhail R. Al-Abed, Adsorption and simultaneous dechlorination of PCBs by GAC impregnated with ZVI/Pd bimetallic particles: Mechanistic aspects and reactive capping barrier concept, Environmental Science and Technology 43 (2009) 488-493.
Joe Williams (firstname.lastname@example.org), National Risk Management Research Laboratory, EPA's Office of Research and Development, 580-436-8608.