Research Fellowships

Emerging Contaminants: Nanomaterials

EPA Office of Research and Development

NSF Graduate Research Internship Opportunities for NSF Graduate Research Fellows

Current as of November 2016

Opportunity Title:

Emerging Contaminants: Nanomaterials

Research Area:

Ecosystems

EPA Lab/Center/Office:

National Exposure Research Laboratory (NERL)

Location:

Athens, GA

Duration:

12 months

Brief Summary:

EPA’s National Exposure Research Laboratory (NERL) conducts research to improve the Agency’s ability to assess human and ecological exposures to environmental stressors. The development and use of new materials being released into the environment presents a challenge in understanding how humans and wildlife may be exposed to them. These emerging contaminants, such as nanomaterials, have increased over the years, yet it is unclear how these contaminants move through the environment once they are released. A team of researchers at NERL is currently researching processes governing the fate and transport of these contaminants, so that we can incorporate them into current environmental fate and transport modeling frameworks.

Opportunity Description:

This position will join a team of researchers investigating the fate and transport of emerging materials in the environment. Currently research is focused on organic nanomaterials (multi-walled carbon nanotubes and graphene oxide), although different emerging contaminants and/or nanomaterials (e.g., titanium dioxide) could be investigated. The research team includes lab experiments, which are designed to understand the processes governing exposure concentrations in the environment, and numerical modelers, incorporating these processes into environmental fate and transport models.

Currently, we are using an updated version of WASP (the Water Quality Analysis Simulation Program, WASP8), an environmental software program for developing models for simulating the fate and transport of contaminants in surface waters and sediments. WASP is a mechanistic, differential, mass balance, environmental fate and transport model, using numerical method techniques to solve the governing equations. A future direction of research may include developing and/or applying watershed models to simulate the fate and transport of emerging contaminants. As part of this project, further research could include: simulating different nanomaterials and different aquatic ecosystems, expanding into exposures to wildlife, simulating nanomaterials in the terrestrial environment, simulating other emerging contaminants of interest, or applying/developing watershed models for nanomaterials.

Part of this research has included updating WASP to include nanomaterial processes. The heteroaggregation of nanomaterials to particles (e.g, silt, clay, POM) is an important process for understanding nanomaterial fate and transport, and this process has been incorporated into the updated WASP version (WASP8). Some nanomaterials can undergo photo-reactions, resulting in the oxidation of the parent compound. For example, graphene oxide can be oxidized and as oxidation occurs it releases polycyclic aromatic hydrocarbons (PAHs). To account for this, light attenuation for 10 different wavelengths have been incorporated into WASP, allowing for the formation of the PAH daughter products. Having these new algorithms incorporated into WASP allows us to investigate an array of different scenarios previously unavailable to water quality modeling.

Opportunities for Professional Development:

This internship will provide the opportunity to work with multi-disciplinary researchers as part of the emerging contaminants research team. The fellow has the opportunity to learn the WASP model, one of the most commonly used water quality models in the world, and learn how to apply it for simulating exposure concentrations of emerging contaminants (nanomaterials) in surface waters and sediments.

Point of Contact or Mentor:

Chris Knightes (knightes.chris@epa.gov)

For more information about EPA Research Fellowship opportunities, visit: /research-fellowships/graduate-research-internship-program-grip-opportunities-epa