This is an award to support research on transport of toxic contaminants in flowing, natural waters involving exchange processes between the stream-flow and the stream sediments which act as storage locations for the contaminants. The research involves investigation of the fundamentals of stream-bed exchange using adsorbing inorganic contaminants and utilizing a five-meter long recirculating laboratory flume with a fine sand bed. Adsorbing inorganic tracers planned for use include bivalent calcium and trivalent aluminum and chromium cations. The investigators plan on using the adsorbable cationic dye tracer methylene blue to establish equilibrium and kinetic behavior of organic contaminants in batch-scale work before proceeding to flume experiments. This project is being jointly supported by the Fluid, Particulate and Hydraulic Systems Program and the Environmental Engineering element of the Environmental and Ocean Systems Program. The relationship of bed-contribution of water pollutants from contaminated sediments to water quality with which those sediments are placed into contact by physical processes influencing the relative motion between sediments and particles disturbed by fluid motion are not well understood. It is expected that results of this research will contribute toward formulation of better models than now exist of interactions between water in motion and sediments contaminated with organic and inorganic pollutants that contaminate the water, and application of those models in environmental and hydraulic engineering practice.
