Predicting the Fate and Effects of Resuspended Metal Contaminated Sediments
Technical Report,01 Apr 2012,01 Oct 2015
University of Michigan Ann Arbor United States
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The over-arching objective of this project was to determine the environmental significance of resuspended metal contaminated sediments, considering spatial and temporal issues as they relate to exposure, fate and real-time vs. ecological effects. The focus was on strong resuspension events, such as those caused by propeller wash, which prevail in harbors and navigation systems. Physical-chemical models were developed that predict metal contaminant speciation, partitioning and transport and the resulting exposures linked to biological effects in these dynamic ecosystems. It appears that most resuspension events,whether conducted in the laboratory or field, are non-toxic events due to the short duration of the exposures. Metals released from sediments are quickly scavenged by Fe and Mn oxyhydroxides becoming non-bioavailable and then settle out onto the surficial sediments. Model results showed that during short-term resuspension events metal bioavailability is limited due to the slow oxidation of metal sulfides, and the binding of released metal to NOM and HFO. The TICKET-PTM was applied to a pilot field test of a propeller-wash event in San Diego Bay as a proof of concept evaluation of the model capabilities. Model results demonstrated the importance of transport, oxidation kinetics and metal partitioning behavior in assessing the effects of propeller-wash events on copper bioavailability in the overlying water.
- Solid Wastes and Pollution and Control
- Physical and Dynamic Oceanography