Environmental safety of contaminants sometimes requires testing at the ecosystem level. Model ecosystems can serve as a surrogate to receiving waters for the assessor. Tools to verify that model ecosystems are good surrogates for natural receiving water systems have been based on structural attributes such as taxa lists.
View Article and Find Full Text PDFTriclosan (TCS) is an anti-microbial agent used in down-the-drain consumer products. Following sewage treatment some of the triclosan will enter receiving waters. This study was designed to determine the die-away rate of triclosan released into a river as part of the sewage treatment plant effluent matrix.
View Article and Find Full Text PDFEcotoxicol Environ Saf
November 2003
Acute and chronic toxicity tests using the cladoceran Daphnia magna were conducted on several alcohol ethoxylate surfactants. Exposure and homologue distributions were confirmed using specific analytical methods. These data were used to test currently available acute structure-activity relationships (SARs) and to develop a new chronic SAR to extrapolate test data to effluent or receiving water mixtures.
View Article and Find Full Text PDFA comparative (15)N-tracer study of nitrogen dynamics in headwater streams from biomes throughout North America demonstrates that streams exert control over nutrient exports to rivers, lakes, and estuaries. The most rapid uptake and transformation of inorganic nitrogen occurred in the smallest streams. Ammonium entering these streams was removed from the water within a few tens to hundreds of meters.
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