Abstract:

Total phosphorus(TP),weakly adsorbed phosphorus(NH4ClP),Albound phosphorus(AlP),Febound phosphorus(FeP),Cabound phosphorus (CaP),residual phosphorus(ResP) and organic phosphorus(OP) in surficial sediment of Dongping Lake were measured by the sequential extraction process.And the distribution of phosphorus fractions were analyzed.The results showed that the average contents of TP were 79538 mg/kg in the surficial sediments of Dongping Lake,which was a little higher than that of the other lakes in China.The phosphorus mainly distributed in inorganic fractions(IP),ranging from 3849 to 1158.3 mg/kg,which accounted for 8076% of TP in the surficial sediments of Dongping Lake.The decease order of different inorganic fractions was CaP>ResP>AlP+FeP> ExpP,accounting for 448%,312%,231% and 09% of IP,respectively.The OP is slightly higher in Laohu pier and midlake,which might be caused by the cage culture and the acceptance of more sewage.The average contents of bioavailable phosphorus was 2458 mg/kg,accounting for 309% of TP in the surficial sediments of Dongping Lake,which indicated that the surficial sediments might be a potential phosphorus source for the overlying water of Dongping Lake.