Physical-Chemical Characterization of Sediments From the Great Salt Lake via FFF-ICP- MS

Sedimentation may be the major effective mechanism of selenium removal from the water column of the Great Salt Lake if there is a permanent sequestration of selenium in deposited sediment. However, re-suspension and re-solubilization of selenium into the water column may also release deposited selenium back to the water column. To quantify these processes the settling phase must be characterized in terms of makeup (e.g. biological versus mineral), size (molecular to particulate), and the selenium burden must be apportioned among these various molecular to particulate fractions in the settling phase. Water column samples were fractionated among dissolved, molecular and particulate sizes using centrifugation and fluid flow fractionation (FFF) and the associated selenium was measured using ICP-MS. This talk presents the results of characterization of the water column via these techniques, and relates these results to results from characterization of deposited sediment.