巢湖及其入湖河流（南淝河）沉积物磷形态与吸附行为的垂直变化

沉积物磷释放可明显促进水体富营养化，但其关键组分与调控因素尚待深入研究。系统分析了巢湖及其入湖河流（南淝河）沉积物有机质(OM)、不同形态磷含量、磷吸附参数的垂直分布特征。结果表明：铁结合态磷(Fe(OOH)~P)与钙结合态磷(CaCO3~P)为沉积物磷的主要存在形态，且均与磷平衡浓度（EPC0）显著正相关。与巢湖相比，南淝河具有明显较高的沉积物最大磷吸附量（Qmax），而由此增强的磷缓冲能力可被较高的Fe(OOH)~P含量所抵消，从而表现出较强的磷释放潜力（高EPC0值）。有机质能以线性方式增加Fe(OOH)~P、CaCO3~P与Qmax，并据此调节EPC0。南淝河沉积物亚表层（10～15 cm）显示EPC0的最小值，从而具有相对较小的磷释放风险

VERTICAL VARIATIONS IN FRACTIONATIONS AND SORPTION BEHAVIORS OF PHOSPHORUS IN SEDIMENTS OF LAKE CHAOHU AND A RIVER(THE NANFEI RIVER) ENTERING IT

The phosphorus release of sediment can significantly prompt water eutrophication,however,its key components and controlling factors remain to be fully researched. In this paper, vertical distribution characteristics of phosphorus sorption parameters and the content of sediment organic matter (OM) and phosphorus forms from large shallow lake (Lake Chaohu) and a river entering it (the Nanfei River) were described systematically.The results suggested that iron bound phosphorus(Fe(OOH)~P) and calcium bound phosphorus(CaCO3~P) were the main forms of sediment phosphorus,and both showed significantly positive relationship with equilibrium phosphorus concentration (EPC0).Compared to Lake Chaohu,the Nanfei River had significantly higher sediment phosphorus sorption maximum(Qmax).This phosphorus buffering capacity was counteracted by higher Fe(OOH)~P content,thus showing obviously strong releasing potential (high EPC0 value).The sediment OM not only enhanced the Fe(OOH)~P and CaCO3~P content,but also gave rise to the Qmax value in linear manners,thereby controlling the EPC0.The sediment EPC0 of the Nanfei River obtained minimum value in subsurface (10-15 cm), so had relatively smaller risk of phosphorus release