(327h) Desorption of Phenanthrene from River Sediment to Water Under Turbulent Conditions

The release of phenanthrene from sediments to water under turbulent conditions was measured for surface sediments collected from the Yangtze River, which is the longest river in China and its basin is the most active economic area of China, in a turbulence system. Batch adsorption and desorption experiments of phenanthrene were performed on two kind of sediments from the Yangtze River in a turbulence system. The results indicated that sorption equilibrium of phenanthrene on the sediments could be achieved within 8 hours. The change of phenanthrene sorption behaviors on the sediments with different grain sizes was mainly caused by the contents of organic carbon in the sediments. The results of hydrodynamic experiments showed that the sediment concentration increased from 1.01 to 6.70 kg/m³ as the hydrodynamic strength increased from 150 to 280 rpm, whereas phenanthrene concentrations in water phase decreased from 0.56 to 0.34 mg/L. Moreover, a sorption dynamic model, which could express the relationship between the diffusive release of phenanthrene and the hydrodynamic parameters, was developed based on the linear isotherm expression and law of conservation of mass to estimate the release of phenanthrene from river sediment to water under different turbulent conditions in the Yangtze River.