Phosphorus fractions and theirs correlation analysis in surface sediment of urban coastal wetland

Phosphorus species and bioavailability(Bio-P) amount in the surface sediment of an urban coastal wetland(Jiulongjiang estuary wetland) were investigated by sequential chemical extraction method.Meanwhile,the relationships among phosphorus fractions and their physicochemical properties were revealed in these sediment samples.Results showed that the content of total P(TP) in the sediment was(456.34±13.13) mg·kg-1,and the percentage of Bio-P accounted for 59.46% of TP.NaOH-P、HCl-P were the main fractions of TP,and the percentage for NaOH-P,HCl-P were 56.74%,33.25% of TP,respectively.NaOH-P was the dominant part of Bio-P,and the percentage for NaOH-P was 95.43% of Bio-P.The correlations among phosphorus fractions indicated that the incremental amount of TP was primarily contributed from NaOH-P,secondly from HCl-P.There were weak correlations among NH4Cl-P,BD-P,NaOH-P,HCl-P,which indicated that their sources were different.NaOH-P was significantly negative correlation with pH,but not correlated to the content of Fe,Al in the sediments.Organic phosphorus(OP) was insignificantly correlated with the content of organic matter.The resluts of this study would supply some basic data for the protection of the ecological system and environmental restoration of Urban Coastal Wetland.