Trace metal loading on water-borne soil and dust particles characterized through the use of split-flow thin-cell fractionation.

The fate and transport of metallic pollutants through a watershed are related to the characteristics of undissolved solid particles to which they are bound. Removal of these particles and their associated pollutants via engineered structures such as settling ponds is one goal of stormwater management. Because the particles most often implicated in metal pollution have nominal diameters of <50 microm, Split-flow thin-cell (SPLITT) fractionation was investigated to study the metal loading as a function of particle settling rate. Several diverse particle samples--soil, urban dust, and parking deck sweepings--were fractionated using this technique, and the metal loadings were quantified with inductively coupled plasma-atomic emission spectrometry. Implications for stormwater management are discussed.