Formation mechanism of bioavailable phosphorus in sediments under the conditions of sediment Re-suspension

The concentrations of different sedimentary phosphorus forms and bioavailable phosphorus were studied and the formation mechanism of BAP in sediments was discussed, under the conditions of sediments re-suspension. The results show that sediment re-suspension had obvious effect on the distribution of different sedimentary phosphorus forms. The BD-P, Al-P, Ca-P were increased evidently and the NH₄Cl-P was decreased with the time of sediment re-suspension extending. The BAP in sediments after re-suspended was reduced by 6.59%, indicating that sediment re-suspension could promote the transformation from BAP to nonbioavailable phosphorus. The formation of AAP might mainly have close relationships with BD-P. After extracting AAP, the BD-P was decreased by 33.4% averagely in the sediments after re-suspended, while the release of BD-P in sediments from the control experiment was increased by 19.8%, showing that the formation of AAP was affected marked by the properties of BD-P. The Olsen-P could be mainly formed from BD-P, Al-P, NaOH-nrP. The formation of Olsen-P was closely correlated to BD-P, based on the release of BD-P, Al-P, NaOH-nrP.