title: Origins and mobility of phosphorus forms in the sediments of Lakes Taihu and Chaohu, China.
abstract: Phosphorus release from the sediment is generally an important factor for lake eutrophication. We have investigated phosphorus forms in surface sediments from Lake Taihu and Lake Chaohu by a chemical extraction method. The results showed that the concentrations of Fe/Al-bound phosphorus (Fe/Al-P) and organic phosphorus (Org-P) had significant correlations with those of amorphous Fe/Al oxides and organic matter in the sediments. Furthermore, Ca-bound phosphorus (Ca-P) concentrations were well related to total organic carbon (TOC) concentrations. The results also indicated that higher pH weakened the association of phosphates with the Fe/Al hydroxides and then resulted in Fe/Al-P release. The increase of pH was companied with autogenetic progresses of calcium carbonate and then elevated Ca-P concentrations in the sediments. In conclusion, external P loadings determine spatial distribution of P fractions, especially Fe/Al-P and Org-P, and partially contribute to additional Ca-P fractions in these highly human-disturbed lakes. The pH-induced phosphorus mobility in the sediments is very important for these lakes.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, The Chinese Academy of Sciences, Beijing, China.
authors.forename: Qing-Hui
authors.initials: QH
authors.lastname: Huang
authors.forename: Zi-Jian
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Dong-Hong
authors.initials: DH
authors.lastname: Wang
authors.forename: Chun-Xia
authors.initials: CX
authors.lastname: Wang
authors.forename: Mei
authors.initials: M
authors.lastname: Ma
authors.forename: Xiang-Can
authors.initials: XC
authors.lastname: Jin
mesh_terms: D000535:Aluminum / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002681:China; D004784:Environmental Monitoring; D005068:Eutrophication; D005618:Fresh Water; D019015:Geologic Sediments / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D000535:Aluminum; D007501:Iron; D002118:Calcium