Towards Understanding Fate and Transport of Engineered Nanoparticles in Stormwater Runoff

As the use of engineered nanoparticles (ENPs) grows, so does the concern for these emerging contaminants in our environment. Despite their tremendous benefits, the inevitable release of ENPs into the environment may be detrimental and hence cause for concern. Stormwater runoff is a key pathway for contaminants like ENPs into rivers, lakes and oceans. Studying ENPs in runoff is extremely important because this is where transformations begin to happen, such as aggregation and/or absorption of natural organic matter, which could and likely effect the fate and toxicity of the ENPs. Existing research is heavily focused on ENPs’ occurrence, fate and transport in wastewater systems, but not to the same extent in the case of stormwater runoff. Our going research is exploring potential fate and transport of ENPs in urban stormwater runoff. More specifically, we are studying fate and transport of ENPs by stormwater source areas (e.g. commercial, residential and industrial) and quantifying how physical (suspended solids, turbidity, etc.) and chemical (pH, conductivity, etc.) properties of stormwater are impacting the ENPs’ fate. We noticed that metallic ENPs tend to aggregate initially (potentially heteroaggregation), while extended turbulence in the system showed disaggregation of the earlier aggregates. We propose to present our observations on how these emerging pollutants are believed to behave in runoff and hence what are some of the target treatment technologies that can be adapted for ENPs’ control and mitigation in surface runoff.