(106e) Phosphorus Fractions and Phosphate Sorption Characteristics of Sediments from the Three-Gorges Reservoir (China) in Relation to the Environmental Conditions I

The phosphorus contents and fractions of four sediment samples collected at the influx of four main branches (CunTan, XiaoJiang, DaNing and XiangXi River) of the Three-Gorges Reservoir on the Yangtze River in China were analyzed by sequential chemical extraction. Adsorption characteristics of sediments for phosphate were studied systematically in batch experiments. The effects of environmental conditions such as pH, temperature, concentration of sediment and salinity on P adsorption were also investigated. The results showed that inorganic P was the major fraction of total P. P adsorption kinetics and the adsorption isotherm could be well described by Simple Elovich model and modified Langmuir model, respectively. P adsorption on the sediments varied with pH. During the range from 6 to 8, P adsorption exhibited a maximum. Higher temperature (278KA293KA303K) accelerated the adsorption of phosphorus, however, higher salinity restrained the adsorption of phosphorus because of the competitive effect.