Project ID: 2006MO63B
Title: Adsorption of the Isoxaflutole Degradate Diketonitrile to Aluminum and Iron Hydrous Oxides
Project Type: Research
Start Date: 03/01/2006
End Date: 02/28/2007
Congressional District:9th
Focus categories: Toxic Substances, Groundwater, Solute Transport
Keywords: Herbicides, contaminants, surface and groundwaters, agrichemicals, IXF, DKN, HAO, HFO, fate and transport, water resources
Principal Investigators: Goyne, Keith W (University of Missouri); Anderson, Stephen H.; Lerch, Robert N.; Lin, Chung-Ho
Federal Funds: $22,000
Non-Federal Matching Funds: $44,833
Abstract: Herbicides used for weed control in agroecosystems are common contaminants in water resources of the United States, and concerns surrounding the presence of herbicides in surface and ground waters are attributable to the toxic and potential carcinogenic effects of these agrichemicals. One agrichemical of concern is the relatively new pre-emergence herbicide isoxaflutole (IXF) used on ~10% of all corn planted in Midwestern states. IXF is rapidly transformed to a diketonitrile degradate (DKN), the active herbicide principle, shortly after field application. This stable and very highly mobile compound has been detected in soil leachate, surface waters, and aquifers of the Midwest. A principle factor governing pollutant fate and transport in the environment is compound interactions with soil components (i.e., sorption processes). We propose to investigate DKN adsorption and retention by hydrous aluminum and iron oxides (HAO and HFO, respectively). These variable-charge minerals have high specific surface areas and reactive surface function groups, thus, they function as major "sinks" for an array of environmental pollutants. Specifically, we will (1) quantify DKN adsorption and retention by HAO and HFO, (2) assess changes in DKN uptake by mineral surfaces as a function of aqueous chemical composition (i.e., pH and initial DKN concentration), and (3) employ infrared spectroscopy to investigate the mechanism(s) through which DKN binds to HAO and HFO surfaces. This research will enhance our understanding of how HAO and HFO in soils and sediments impact environmental fate and transport of DKN. A thorough understanding of DKN sorption processes will enhance predictive capabilities of pollutant transport models and aid in identifying soil characteristics that reduce DKN migration to water resources.
Progress/Completion Report, PDF