Study on Phosphorus Characteristics in Sediments of Xiangxi Bay, China Three-Gorge Reservoir

Abstract

To explore the environment influence of the sediments in Xiangxi Bay (China Three-Gorge Reservoir), spatial and temporal distribution characteristics of total phosphorus (TP), phosphorus fractions, dissolved total phosphorus (DTP) of pore water and overlying water in the sediments were investigated. In surveys, the sampling was undertaken from six sites of Xiangxi Bay on 29 March 2009 and 28 March 2010. TP contents ranged from 1111.29 mg/kg to 1941.29 mg/kg with the mean value of 1533.09 mg/kg in 2009 spring and 1600.48 mg/kg in 2010 spring. Five fractions of sedimentary phosphorus, including loosely sorbed phosphorus (NH 4 Cl-P), redox-sensitive phosphorus (BD-P), metal oxide bound phosphorus (NaOH-P), calcium bound phosphorus (HCl-P), and residual phosphorus (Res-P), were separately quantified. DTP of pore water and overlying water all have positive correlations with NH 4 Cl-P and BD-P, which indicated that NH 4 Cl-P and BD-P were the main fractions that can easily release phosphorus in the sediments of Xiangxi Bay.