The geometry of a river bed surface is determined by the arrangement and size of the particles that form the bed. In gravel-to-boulder bed rivers, the surface geometry around any individual particle may be complex and highly variable, and tends to include multiparticle structures. These textural and structural characteristics influence whether an individual particle is entrained. The effect on ...

Bacterial communities associated with sediment particles were examined using PCR-denaturing gradient gel electrophoresis and 16S rRNA gene sequencing. Particle size influenced community structure, with attached bacterial assemblages separating into 63- to 125-, 125- to 1,000-, and 1,000- to 2,000-microm fractions. Differences were particularly pronounced for the Verrucomicrobia-Planctomycetes, ...

A laboratory based microcosm study utilising intact non-sterile sediment cores was undertaken to determine the survival of the faecal indicator organisms Escherichia coli, Enterococcus faecium and somatic coliphage in both recreational coastal water and sediment. Overlying water was inoculated with the test organisms and incubated at 10°C, 20°C or 30°C. E. coli, enterococcus and coliphage were ...

The performance of vegetative filter strips is governed by complex mechanisms. Models can help simulate the field conditions and predict the buffer effectiveness. A single event model for simulating the hydrology and sediment filtration in buffer strips is developed and field tested. Input parameters, sensitivity analysis, calibration and field testing of the model are presented. The model was ...

Title of Document: MODELING THE IMPACT OF SEDIMENT RESUSPENSION AND FLOCCULATION ON THE FATE OF POLYCHLORINATED BIPHENYLS. Chihwei Chang, Doctor of Philosophy, 2008 Directed By: Professor Joel E Baker, University of Maryland, Chesapeake Biological Laboratory Hydrophobic organic contaminants (HOCs) are important pollutants in urban estuaries. HOCs include polycyclic aromatic hydrocarbon (PAH), p...

In this study SiltSaver belted strand retention fence was compared with traditional type C silt fence with the goal of determining if it would be acceptable for use as a sediment barrier in Georgia. ASTM standard methods were used to evaluate flow through and sediment removal efficiency using three different site specific soils. For flow without sediment, there were no statistical differences, ...

A Large Eddy Simulation of a fully developed turbulent open-channel flow with Reynolds number Re=71,755 was performed to study dynamics coherent structures in the vicinity stationary sediment particle. The particle positioned at bottom on smooth channel bed. impulse concept employed by computing three-dimensional hydrodynamic forces acting order predict onset motion. Results quadrant analyses h...