In order to investigate the cycling of phosphorus in the Taihu Lake, a sequential extraction technique was used to separate different phosphorus forms in surficial sediments from the Wuli Bay of the Taihu Lake. The co...In order to investigate the cycling of phosphorus in the Taihu Lake, a sequential extraction technique was used to separate different phosphorus forms in surficial sediments from the Wuli Bay of the Taihu Lake. The concentrations of total P are high in the sediments, with an average of {2.80} mg·g+{-1}, and a variation range between {4.02} and {2.05} mg·g+{-1}. Total P is composed mainly of inorganic P (70%-90%), a large portion (75%-85%) of which lies in the CDB-extractable iron oxide phase. The low Fe/P atomic ratios ({2.0}-{5.3}) indicate that the Fe compounds extracted with CDB have a lower proportion of relatively crystalline phases in all samples, and that the absorption between iron and phosphorus has probably reached certain equilibrium. Organic C/N atomic ratios ({8.8}-{10.6}) for most of the samples are lower, which suggests a lacustrine authigenic source of organic matter in the sediments. Moreover, organic C/P atomic ratios (135-320) are usually higher than the Redfield ratio (106∶1), showing that the organic phosphorus had been preferentially released via organic matter degradation during the early diagenesis process.展开更多
文摘In order to investigate the cycling of phosphorus in the Taihu Lake, a sequential extraction technique was used to separate different phosphorus forms in surficial sediments from the Wuli Bay of the Taihu Lake. The concentrations of total P are high in the sediments, with an average of {2.80} mg·g+{-1}, and a variation range between {4.02} and {2.05} mg·g+{-1}. Total P is composed mainly of inorganic P (70%-90%), a large portion (75%-85%) of which lies in the CDB-extractable iron oxide phase. The low Fe/P atomic ratios ({2.0}-{5.3}) indicate that the Fe compounds extracted with CDB have a lower proportion of relatively crystalline phases in all samples, and that the absorption between iron and phosphorus has probably reached certain equilibrium. Organic C/N atomic ratios ({8.8}-{10.6}) for most of the samples are lower, which suggests a lacustrine authigenic source of organic matter in the sediments. Moreover, organic C/P atomic ratios (135-320) are usually higher than the Redfield ratio (106∶1), showing that the organic phosphorus had been preferentially released via organic matter degradation during the early diagenesis process.
