连续提取和液体磷核磁共振表征太湖梅梁湾沉积物中磷的剖面分布(英文)

Phosphorus speciation in sediment profile of Meiliang Bay, Taihu Lake by sequential fractionation and solution phosphorus-31 nuclear magnetic resonance spectroscopy

应用连续提取法(SMT)和液体磷核磁共振(31P NMR)技术研究了太湖北部梅梁湾沉积物中磷形态和组成的剖面变化。结果表明,铁/铝磷是沉积物中磷的主要形态,约占总磷含量的 44.0–54.6%。总磷、无机磷、有机磷和铁/铝磷含量均随沉积深度增加呈降低趋势,至 18 cm 以下略有增加,而钙磷却在柱样下部随沉积深度增加呈累积趋势。31P NMR 显示,沉积物磷主要由正磷酸盐(72.0-99.2%)和磷酸单酯(0.8-25.9%)构成,磷酸二酯、膦酸盐和焦磷酸盐的相对含量非常低,分别为 1.0%、0.4–1.0%和 0.1%。正磷酸盐含量在沉积物表层 9 cm 内减少了 65%,9 cm 以下波动变化,但总体呈降低趋势。这些特征表明沉积物中磷对梅梁湾上覆水体具有强烈的释放潜力,是太湖富营养化发生的重要因素。

Lake sediments are considered a sink as well as a source for nutrients and, therefore, play a decisive role in the phosphorus （P） metabolism in lakes. The amount of mobile P in the sediments is an important parameter for predicting internal loading whichwill often determine the trophic status of the lake and the time lag for recovery after the reduction in external loading. Therefore, the P behavior in lake sediments can be efficiently evaluated based on the P fractions or speciation, instead of the total P content.