Composition, structure and size distribution of suspended particulates from the Rhine River

Fluvial suspended particulates collected from the Rhine River were investig ated in terms of composition. structure and size distribution. Elemental an alysis and Diffuse Reflectance infrared Spectroscopy reveal that most parti culate organic matter is formed from material derived from microorganisms. Transmission Electron Microscopy observations on resin-embedded samples and structural characterization from break-up experiments. show that fluvial p articulate matter should be viewed as fractal aggregates organized by bacte rial exopolymeric substances. The shape of particulate size distribution su ggests that the formation and dynamics of suspended particulate matter are controlled mainly by physical processes. Finally, particulate growth and st ructure are consistent with a cluster-cluster agregation scheme. (C) 2001 E lsevier Science Ltd. All rights reserved.