HR: 0800h
AN: H21C-1031    [Abstracts]
TI: Cycling of Organoarsenic Compounds in Agricultural Watersheds
AU: * Schreiber, M E
EM: mschreib@vt.edu
AF: Dept Geosciences, Virginia Tech, 4044 Derring Hall, Blacksburg, VA 24061 United States
AU: Chambers, D B
EM: dbchambe@usgs.gov
AF: U.S. Geological Survey, Water Resources Division, 11 Dunbar St, Charleston, WV 25301 United States
AU: White, J S
EM: jswhite@usgs.gov
AF: U.S. Geological Survey, Water Resources Division, 11 Dunbar St, Charleston, WV 25301 United States
AB: The use of the organoarsenical roxarsone, added to poultry feed to increase weight gain, results in elevated arsenic concentrations (10-50 mg/kg) in poultry litter. This litter is extensively applied to crop fields and pastures, both as a fertilizer and as a waste disposal technique, in agricultural regions. Using a combination of field sampling and laboratory experiments, we investigated the sources and sinks of arsenic within soils and natural waters in an agricultural watershed in the Shenandoah Valley of Virginia, USA, an area of intense poultry production. Surface, ground, and soil waters were collected in an instrumented field site to examine arsenic and other litter-derived species in different hydrologic compartments and different settings within the field site. We collected soil cores of the Frederick series, common in the Shenandoah Valley, from several areas experiencing different litter application histories in the valley to examine relationships between arsenic and physico-chemical properties of the soils. Last, we conducted a series of batch experiments to examine adsorption and biotransformation characteristics of roxarsone within Ap and Bt soil horizons of the Frederick soils. Results of these combined studies document a complex yet intriguing cycling of arsenic through the watershed, which will provide useful information for management of poultry litter in agricultural watersheds.
DE: 1806 Chemistry of fresh water
DE: 1832 Groundwater transport
DE: 1065 Trace elements (3670)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting