Water Resources and Power

In order to explore the evolution of small and medium eutrophic lakes and understand the distribution of Phosphorus forms in sediments,Dazong Lake in Lixiahe Area of Jiangsu Province was taken as an example.Based on improved Phosphorus separation method,the vertical distribution of Phosphorus fractions in sediment from three different sampling points of Dazong Lake were analyzed.And then the potential release capacity of Phosphorus from the vertical sediments and their sources were discussed.The results show that DZ1sampling point held the highest TP content in the sediments,TP content of DZ2and DZ3sampling points was almost the same;De-P and Or-P had made a huge contribution to the TP;Ex-P,ACa-P and De-P were significantly associated with the bio-available Phosphorus,which had a potential risk of the release of Phosphorus;active Phosphorus was made up of Ex-P,Fe-P and Al-P,which was given priority to Ex-P;the descended ranking sequence of the contents of four kinds of BAP was as follows:AAP,Olsen-P,WSP, RDP;the contents of AAP and Olsen-P in sediments decreased exponentially with increase of sediment depth.