A Comprehensive Modeling Approach for Predicting Nanoparticle Fate and Transport in Porous Media Under Varying Geochemical ConditionsEPA Grant Number: FP917312
Title: A Comprehensive Modeling Approach for Predicting Nanoparticle Fate and Transport in Porous Media Under Varying Geochemical Conditions
Investigators: Becker, Matthew D
Institution: Tufts University
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2011) RFA Text | Recipients Lists
Research Category: Fellowship - Water Quality: Hydrogeology and Surface Water , Academic Fellowships
Available laboratory data suggest that background solution chemistry conditions including, but not limited to, ionic strength and composition, solution pH, and presence of natural organic matter will strongly influence the deposition and re-entrainment behavior of nanoparticles in homogeneous and heterogeneous porous media. The goal of this project is to develop a tool that can effectively predict transport of common manufactured nanoparticles in the subsurface using inputs pertaining to characteristic features of the particles, porous media and background solution chemistry.
Approach:Using clean-bed colloid filtration theory as a basis, functional relationships will be developed that describe how nanoparticle attachment and detachment parameters change with variations in solution ionic strength, pH and presence of other aqueous constituents. The model will be calibrated using published data from transport experiments under various conditions and experimental data currently being produced in the Pennell laboratory at Tufts University. Through analysis of model sensitivity to changes in input parameters, governing parameters and mechanisms of transport and deposition can be further understood. Later, this model will be scaled up to more field-relevant scales and implemented in multiple dimensions to understand transport behavior and the potential pathway of exposure in more realistic scenarios.
This project will create a useful tool in assessing the contamination potential of groundwater resources due to releases of manufactured nanoparticles. Using the developed model’s results as a guide for what may occur under ideal conditions, experimental results can be further explored to understand the influence that complex background solution chemistry characteristics have on particle deposition. The inherent value of coupling model development and calibration with experimental data is the ability to relate laboratory results to the prediction of potential contamination scenarios for nanoparticle release at the field scale. This research also will provide another tool upon which scientists and policy makers can consult in decisions regarding regulation of nanoparticles and other similar emerging contaminants.
Potential to Further Environmental / Human Health Protection
Currently, regulations controlling nanoparticle release into the environment virtually are nonexistent. To implement such policies, understanding of the fundamental mechanisms of nanoparticle behavior in environmentally relevant solution chemistries must be built upon. Through more informed modeling of nanoparticle fate and transport, the scientific community will be better able to relate existing and future toxicity studies’ results to the potential environmental and public health threats that these materials might pose.