巢湖沉积物有效磷的原位高分辨分析研究

将两种原位被动采样技术——高分辨平衡式间隙水(HR-Peeper)与氧化锆薄膜梯度扩散技术(Zr-oxide DGT)相结合,分别对巢湖西半湖7个点位溶解态反应性磷(cPW)和有效磷(cDGT)进行原位测定分析,cPW和cDGT在大部分沉积物剖面的分布相似或局部相似,说明不同深度沉积物固相有效磷组分对间隙水SRP的缓冲能力较接近.利用界面扩散通量和cDGT/cPW比值(R)表征沉积物磷的活性,从巢湖湖心向南淝河入湖口方向,界面以下6 mm的cPW、cDGT和扩散通量的变化基本一致,均呈递增趋势,表明沉积物磷的污染水平在增加;R值变化较小,说明沉积物界面处的缓冲能力差异不明显.

In Situ High-Resolution Analysis of Labile Phosphorus in Sediments of Lake Chaohu

High-resolution pore water equilibrators (HR-Peeper) and diffusive gradients in the thin films (DGT) technologies were combined to in situ measure soluble reactive phosphorus (c_PW) and labile phosphorus (c_DGT) on seven sites in the west of Lake Chaohu. Vertical distributions of c_PW and c_DGT in most sediment profiles were similar to a different extent, demonstrating that the buffer capacity of the sediment solids to pore water SRP was similar at different depths. The diffusion flux across the sediment-water interface (SWI) and the ratio of c_DGT/c_PW (R) were used to characterize phosphorus activity in sediments. From the center of the lake to the estuary of Nanfei River, the values of c_PW and c_DGT within the 6 mm layer were below the SWI and the SWI diffusion flux gradually increased, reflecting an increase in pollution level of sediment phosphorus. The change of R values was unconspicuous, indicating that the buffering capacity of the interface sediment had no significant difference.