摘要
Total P(TP),organic P(OP) and different forms of inorganic P(IP) were analyzed by using the seven-step sequential extraction method in different sediments from Lake Hongze.Distribution characteristics of P in different sections and its impact on the natural water column were discussed.The results indicated that the contents of TP in all sediment samples range from 630.6~1403.4 mg·kg-1 and IP is its dominant portion,accounting for 67.7%~83.6% of TP.OP accounts for 16.4%~32.3% of TP.Their maxima all appear in Linhuai Township near the entrance of the Huai River and Sui River to Lake Hongze.IP includes six forms of phosphorus: exchangeable P(Ex-P),aluminum-bound P(Al-P),iron-bound P(Fe-P),occluded P(Oc-P),authigenic carbonate-bound P(Ca-P) and detrital P(De-P).De-P and Fe-P were found to be the major components of IP whose contents are 25.1%~37.3% and 18%~35.5% of TP,respectively.The contents of Ex-P,ACa-P and Al-P are all lower and those of Oc-P are lowest.Correlation analysis showed that TP is positively correlated with IP and poorly correlated with OP.IP strongly influences the contents of TP in sediments.