Phosphorus Speciation in Sediments of the Yongding River and Its Significance

Sediments were sampled near the Yongding River estuary. The sampling depth was 77 cm and was separated into 77 layers. 11 layers of samples were chosen to determine total phosphorus (TP) and the sequentially extracted Ca_(2)-P, Ca_(8)-P, Al-P, Fe-P. Org-P