Effect of sediment physicochemical properties on phosphorus sorption for different size particles
不同粒径泥沙理化特性对磷吸附过程的影响

The surface sediments samples were collected from Nanhaizi Lake in Beijing. The phosphorus sorption behaviors on four particle size sediments including 0.147~0.246 mm(fine sand), 0.074~0.147 mm (very fine sand),0.0385~0.0740 mm(silt),<0.0385 mm (mixture of silt and clay) were determined. The effects of sediment organic matter (OM), TP, Fe, Ca,Al and Mn on phosphorus sorption were analyzed using correlation analysis and stepwise regression. The results showed that the second order kinetics model and Langmuir isotherm equation could well describe the behaviors of the phosphorus sorption with determining coefficients R2 of>0. 90). The maximum sorption mass (Xm) of different size particles was in the order of silt and clay>silt>fine sand>very fine sand. The content of OM, TP, Fe, Ca, Al and Mn increased with the decreasing particle size and the fraction of clay particles had more important effect on them than other particles. There was a significantly positive correlation (P<0.01) among the content of Fe,Ca,Al,Mn,OM. All these chemical compositions, especially Al, had a clearly positive effect on the Xm and equilibrium concentration (Cse) on the sediments. These results indicate that the phosphorus sorption could be jointly affected by both sediment particle size and chemical composition.