Variation of bioavailable phosphorus under sediment disturbance with high intensity

A lab-scale experiment was conducted to investigate the variation of bioavailable phosphorus(BA) and the distribution of sedimentary phosphorus forms under sediment disturbance.The results showed that the distribution of sedimentary phosphorus forms changed on the suspended solids during the disturbance.Labile phosphorus(NH4Cl-P) and Fe/Al-P presented the decreasing tendency,Ca-P increased first and then decreased finally,and Res-P was increased generally.This proved that the disturbance promoted the variation of sedimentary phosphorus from easy releasing type to non-releasing type.The concentration of algae available phosphorus(AAP) in the overlying water increased from 0.026 mg/L(Meiliang Lake) and 0.032 mg/L(Moon Bay) to 0.044 mg/L and 0.051 mg/L,respectively.The concentration of bioavailable particulate phosphorus(BAPP) was increased first and then decreased with the maximum value of BAPP in Meiliang Lake and Moon Bay was 207 and 171 mg/kg respectively.It is suggested that sediment disturbance contributed to the transformation of phosphorus forms on the suspended solids.