Experiments were designed to answer key questions about diatom-derived organic matter cycling (i.e., production and degradation) in coastal systems. Dissolved organic matter (DOM) production was examined in axenic batch cultures of five diatom species. Dissolved organic carbon (DOC) release rates varied between species, but were significantly higher for all species...
This report presents results of an investigation of water and streambed-sediment quality in selected tributaries of the South Umpqua River. Concentrations of inorganic constituents in water (major and minor ions, nutrients, and trace elements) and streambed sediment (primarily trace elements), along with standard field parameters, are tabulated for samples collected...
The atmospheric transport of anthropogenic semivolatile organic compounds (SOCs) from Asian sources to the Western U.S. was investigated. In addition, the SOC extraction method was optimized. Hansen solubility parameter plots were used to aid in the pressurized liquid extraction (PLE) solvent selection of air sampling media in order to minimize...
More than 65,000 organic chemicals are currently in commercial production with
approximately 1000 added each year. Many chemicals are released into the environment as organic mixtures derived from complex hazardous or solid wastes. Of these, more than 1000 chemicals are of environmental concern because of their production quantities, toxicity, persistence,...
The use of semi-volatile organic compounds (SOCs) as molecular markers to identify the contributions of regional and long-range atmospheric transport, as well as current and historic sources, and contaminant deposition in remote ecosystems of the Western U.S. was investigated. Trans-Pacific air masses influenced by Siberian biomass burning events had elevated...
The seasonal distribution of bioavailable organochiorine contaminants in surface
water and the potential environmental factors influencing their bioavailability were
evaluated. The study was carried at the lower Willamette River at Portland Harbor, Oregon
where surface water runoff varied according to season. Bioavailable water concentrations of
DDTs and PCBs were determined...
Sources of polar/water-soluble organic compounds conjunctly with apolar biomarkers were characterized in natural organic matter. This multi-biomarker approach was accomplished by a simple analytical method consisting of extraction with dichloromethane:methanol (2:1, v/v), silylation and analysis by gaschromatography- mass spectrometry (GC-MS). Polar and apolar biomarkers, derived mainly from higher plants and...
Ambient high-volume (hi-vol) air samples were collected between March 15th and May 30th 2002, at Cheeka Peak Observatory (CPO), located on the tip of the Olympic Peninsula, Washington State. This sampling campaign was in conjunction with the 2002 Inter-Continental Transport and Chemical Transformation (ITCT 2K2) Campaign and the Photochemical Ozone...