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VARIABILITY OF PARAMETERS MEASURED DURING THE RESUSPENSION OF SEDIMENTS WITH A PARTICULATE ENTRAINMENT SIMULATOR
Citation:
Cantwell, M AND R M. Burgess. VARIABILITY OF PARAMETERS MEASURED DURING THE RESUSPENSION OF SEDIMENTS WITH A PARTICULATE ENTRAINMENT SIMULATOR. Presented at Society of Environmental Toxicology and Chemistry Annual Meeting, Salt Lake City, UT, November 16-20, 2002.
Description:
Contaminated sediments are a problem facing many environmental managers concerned with issues such as maintenance dredging, habitat restoration and dredged material placement. Currently, there are few methods which can be used to assess contaminant remobilization potential from resuspended sediments. Most procedures in use do not reflect conditions which sediments are exposed to in the field. This laboratory study was conducted to evaluate the magnitude of variability when using a particle entrainment simulator (PES) for resuspending marine sediments and measuring the mobilization of environmentally significant metals. Metals concentrations and water column conditions were measured using three sediments with different physical and chemical characteristics. Resuspensions were performed at an energy of 5 dynes cm-2 for a twelve hour period. The magnitude of variability was determined by resuspending sediments in triplicate under identical conditions. Variability is reported as the coefficient of variation (CV). Metals in the dissolved phase showed few trends with the magnitude of variation being attributable to sediment composition. In the water column CVs for pH remained below 3%, while dissolved oxygen CVs dropped from 40% to 10% during the test. Redox levels were the most variable, ranging from 140% at the start of the experiment, dropping to 17% by hour 12. Results of this study demonstrate the magnitude of variability associated with the PES are minor compared to those of the sediments being manipulated.