Distribution of Metals in Different Size Fractions of Sediment from the Niagara River

Abstract

This study was carried out to demonstrate that the concentration of major and trace elements, determined in sediment samples separated mechanically into different size fractions, gives better information for assessing a potential hazard of in situ, dredged, or resuspended sediments than the bulk total concentration. The concentrations of major elements (Si, Al, Ca, Mg, Na, K, Fe, Ti, Mn, and P), trace elements (Cr, Co, Cu, Zn, V, Ni, and Pb), and organic and carbonate C were determined in six size fractions (< 13 μm, 13–19 μm, 19–27 μm, 27–40 μm, 40–54 μm, and 54–150 μm) of bottom sediments collected at eight stations along the Niagara River. Fine particles (< 13 μm) separated from the river sediments exposed to pollution sources accumulated greater metal quantities than particles in the other size fractions. The contribution of trace elements from specific size fractions was calculated from the particle size distribution and trace elements concentration. With the exception of Ni, significant differences were found between trace elements concentration in specif ic particle size fractions of Niagara River sediments and that from the nearshore zone of Lake Erie.