The diffusion fluxes and sediment activity of phosphorus in the sediment-water interface of Poyang Lake

摘要

The dissolved reactive phosphorous (DRP) in pore water releases into the water body through the sediment-water interface. The DRP concentrations in the water and sediment of Poyang Lake were determined by high-resolution pore diffusion balance (HR-Peeper) and Zr-oxide diffusive gradients in thin films (Zr-oxide DGT) techniques. The range of the DRP concentrations in the pore water samples of different sampling sites was 30-360 ng/cm(3). The diffusion fluxes of DRP in the sediment-water interface were calculated based on the DRP concentration gradients. The range of DRP flux in Poyang Lake was 4.78-40.5ng m(-2) d(-1) with an average value of 14.7ng m(-2) d(-1). The results showed that the P diffusion flux was higher in the middle of the Poyang Lake than both upstream and downstream of the lake.