Grantee Research Project Results
The Role of Soils and Sediments in the Fate and Transport of Chemicals Indicative of Non-Point Sources of PollutionEPA Grant Number: F07F10973
Title: The Role of Soils and Sediments in the Fate and Transport of Chemicals Indicative of Non-Point Sources of Pollution
Investigators: Starck, Shannon R.
Institution: University of North Carolina at Chapel Hill
EPA Project Officer: Just, Theodore J.
Project Period: August 16, 2007 through August 16, 2009
RFA: STAR Graduate Fellowships (2007)
Research Category: Engineering and Environmental Chemistry , Fellowship - Environmental Science , Academic Fellowships
Anthropogenic contaminants are finding their way into the environment in increasing amounts through point and non-point sources of pollution. Non-point sources of pollution, which are caused by the movement of water originating in part from rainfall, snowmelt, or irrigation practices across and through the soil, are of particular concern as they are not regulated. Due to adsorption, soils can become sinks for contaminants playing a role in their persistence in the environment since the rate of sorption to organic carbon in soils and sediments affects the bioavailability of contaminants. Alternately, rainfall events and irrigation practices can effect the partitioning of contaminants back into the aqueous phase or cause the soil to erode, in either case transporting the contaminant into nearby surface water. Once migrated in this way, soils and sediments can then play a role in the persistence of the contaminant in the environment. The goal of this study is to determine the effect soils and sediments have on the persistence of contaminants originating from non-point sources of pollution and on compromised water quality.Approach:
The role soils and sediments play in the fate and transport of contaminants indicative of non-point sources of pollution will be assessed. For this study, representative contaminants will be chosen based on their persistence in the environment and their absence from point sources of pollution. Batch isotherm experiments will be conducted to examine the adsorption and desorption of these contaminants in respect to soils with varying amounts of soil organic matter and textures similar to those found in the Piedmont region of North Carolina: sand, clay, and loam. A simulated river environment will then be constructed and the characteristics of sediment free of anthropogenic inputs characterized. The fate and transport of contaminants in the soil, sediment, and aqueous phases will be determined using gas chromatography with mass selective detector or high performance liquid chromatography with electrospray mass spectrometry, depending on the analyte. In addition, the transport of non-point sources of contaminants will be monitored through development of synchronous scan fluorescence matrices to show the potential of this technique for rapid detection of changes in surface water quality.Expected Results:
This research will show whether adsorption of anthropogenic chemicals in soils and sediments impacts their persistence in the environment particularly with respect to their presence in surface waters. Moreover, a fluorescence matrix technique will be evaluated as a tool to rapidly detect changes in surface water quality resulting from non-point pollution runoff. These findings will address concerns over current practices that transport synthetic chemicals to water supplies by demonstrating whether such practices are compromising water quality.Supplemental Keywords:
Soil, sediment, non-point source pollution, contaminant, detection, runoff, transport, drinking water, environmental chemistry, organic matter, water, water quality, batch isotherm, simulated river environment, anthropogenic, fluorescence,