Forms of Phosphorus and Silicon in Surface Sediments

The geochemical phases of phosphorus are the important parameters that reflect the bioavailability and ecological effects of phosphorus. As is well known, aqueous phosphate shares with nitrate the characteristic of being a major growth-limiting nutrient in the global biosphere, and apatite and iron oxide weathering are the major aquatic supplies. 

The OSF-P was the main form of transferable phosphorus, and was influenced to a considerable degree by the redox properties of the sedimentary environment. 

Of the forms of transferable phosphorus in surface sediments, OSF-P was the predominant form, accounting for 10.7% of the total phosphorus CF-Si was the predominant form of transferable silicon, accounting for 0.05% of the total silicon. There was a certain similarity in the diagenesis of various forms of phosphorus. The content of the transferable form of silicon accounted for less than 0.12%, indicating that previous research on the biogeochemical process of silicon by means of the determination of the total silicon content cannot give us any valuable information (Song et ah, 2003). 

2 Biogeochemical Processes of Phosphorus and Silicon of Surface Sediments in the southern Bohai Sea 

Earlier research indicated that many factors affect the contents and distributions of P and Si in sediments as well as P and Si transfer across the sediment seawater interface. Marine sediments are an important source and sink of P and Si in sediments and have more important functions than scientists considered before. Hence, it is necessary to ascertain which factor has the largest impact on the cycling (release and burial) of P and Si in the southern Bohai Sea. In other words, the major factor controlling the interface cycle of P and Si must be determined. 

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