Vertical Distribution and Dynamic Release Characteristics of Pollutants from Resuspended Sediment

Abstract

The pollutant-containing sediments are subjected to re-suspension due to complex hydrodynamics. This study focuses on the relationship of vertical distributions between pollutants and re-suspended sediment. The transportation processes of resuspended sediment on a series of uniform flow were conducted in a flume. Reactive tracer (phosphorus) was used as the contaminants in fine-grained sediments in order to indentify the release characteristic length and time. Experimental results showed that the suspended solid concentration (SSC) decreased with the distance, water depth and particle grain size. TP concentration changed along the water depth as SSC on the initial re-suspension stage, which appears two obvious concentration regimes: the upper low-concentration layer and the high-concentration near-bottom layer. This layered phenomenon lasted about 3 hours until SSC distribution tended to be uniformed