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APPLYING TOXICITY IDENTIFICATION PROCEDURES TO FIELD COLLECTED SEDIMENTS
Citation:
NorbergKing, T J., D. R. Mount, V R. Mattson, T L. Highland, L J. Heinis, J. R. Hockett, C. T. Jenson, AND E N. Leonard. APPLYING TOXICITY IDENTIFICATION PROCEDURES TO FIELD COLLECTED SEDIMENTS. Presented at Developing the Causal Analysis/Diagnosis Decision Information System (CADDIS), Deer Creek State Park, Columbus, OH, August 26-28, 2002.
Description:
Identification of specific causes of sediment toxicity can allow for much more focused risk assessment and management decision making. We have been developing toxicity identification evaluation (TIE) methods for contaminated sediments and focusing on three toxicant groups (ammonia, cationic metals, and non-polar organic toxicants) in solid phase sediment tests. Initial tests were conducted with 10-d solid phase toxicity tests with freshwater organisms, Hyalella azteca and Chironomus tentans on field collected sediments. When toxicity was confirmed, initial characterization tests were conducted with bulk sediments. Characterization manipulations to the bulk sediment were made. For metal reduction these included using zero-valent Mg, iron, and sulfide salt additions to enhance acid volatile sulfide (AVS) and a cation exchange resin. For organic toxicant removal, two sorbents, coconut charcoal and Ambersorb resins, were used. Zeolite additions were used to reduce pore water ammonia and any associated toxicity. Toxicity tests were then conducted with the amended sediment samples to determine the efficacy of each for removing toxicity. The relative effectiveness of each manipulation provides information on the type(s) of chemicals responsible for toxicity. This paper presents a brief summary of these methods along with data from their application to field-collected sediments. This abstract does not necessarily reflect EPA policy.