[Impacts of Multiple Disturbance on Migration and Transformation of Endogenous Phosphorus in Lake]

This work aimed to clarify the influence of multiple disturbance factors on the migration and transformation of endogenous phosphorus. In this experiment, the sediment of Meiliang Bay in Taihu Lake was studied as the major research object. With the help of Rhizon sampling technique, Unisense microelectrode system and so on, this experiment studied the change regularities of dissolved oxygen between sediment and water interface, different forms of phosphorus and iron ions under disturbance. The results indicated that the dissolved oxygen content in sediment decreased in the presence of Corbicula fluminea as compared with the control experiment. Disturbance made the peak area of DIP in interstitial water to migrate from 3-4 cm to 4-5 cm, which suggested that the "active region" of DIP regeneration went deeply into sediment with the appearance of Chironomus plumosus and Corbicula fluminea. Meanwhile, the existence of Corbicula fluminea and algae further reduced DIP in the interstitial water. That was because the released NH₄Cl-P was transferred to phosphorus in overlying water and Fe/Al-P. With the increase of disturbance factors, the transformation ratio from NH₄Cl-P to Fe/Al-P also increased gradually (from 44% to 59%).