文摘
Organic phosphorus (OP) species in sediments of the Baiyangdian Lake in China was investigated via fractionation and phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy. Results of chemical fractionation showed that different OP fractions ranked in the order: humic acid8211;P > HCl8211;OP > fulvic acid8211;P ≈ NaHCO38211;OP > residual OP. Labile OP and moderately labile OP, which can be degraded for phytoplankton uptake, contributed to 58.78211;68.5% of total extracted OP, indicative of the potential P release from sediments in the lake. 31P NMR spectroscopy results suggested the rank order of P species present in the NaOH8211;EDTA extractant of the sediments: orthophosphate > monoester8211;P > DNA-P > pyrophosphate8211;P. Phytate, polyphosphates, and phosphonates, which appeared in sediments of some deeper lakes, were not detected in the shallow lake. Significant correlations were identified between total P (TP) in water column and sediment TP, monoester8211;P and DNA-P, positively indicating that sediment P species, especially OP components, should probably contribute to the contents of P in water column and further to the lake eutrophication.