title: [Phosphorus fractions, sorption characteristics and its release in the sediments of Yangtze Estuary Reservoir, China].
abstract: To analyze the sediment phosphorus (P) fractions and sorption characteristics and P release from sediment of reservoir in Yangtze estuary, the sediment was investigated during April, 2011 to January, 2012. Results of chemical fractionation analysis showed that total P (TP) content in sediment ranged from 535.07 to 910.9 mg x kg(-1), inorganic P (IP) was a dominant component of TP and the content of organic P (OP) was low. IP presented in the form of P bounded to calcium ( HCl-P) and dominated 75.57% of TP. The batch experiments showed that sediments had the maximum P adsorption capacity from 9.78 to 39.84 mg x kg(-1), sorption data fitted the modified Langmuir isotherm model. However, EPC0 ( equilibrium phosphorus concentration) in all sampling sites was higher than the soluble-reactive P concentration in water column, which was from 0.024-0.12 mg x L(-1). Accordingly, the sediments from those sampling sites would release phosphorus into the overlying water as a P release source. The maximum released amount from sediment was 11.03 mg x kg(-1) about 6 hours. Correlation between P released amount and NaOH-P was found (P < 0.01), and sediment P release would mainly originate from the NaOH-P, OP and HCl-P fraction. It is evident that the inherent phosphorus present in sediments would be a major threat to the water quality in Yangtze River estuary reservoir.
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Jin
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Chen
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Song
authors.forename: Yi-Liang
authors.initials: YL
authors.lastname: He
mesh_terms: D000327:Adsorption; D002681:China; D004784:Environmental Monitoring; D063366:Estuaries; D019015:Geologic Sediments / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis*; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus