title: Sequential fractionation of phosphorus in sediments of El-Fayum lakes--Egypt.
abstract: The amounts and forms of potentially mobile phosphorus (P) in surface sediments of Qarun and Wadi El-Rayan lakes were evaluated during winter and summer using a sequential chemical extraction. Five sedimentary P fractions were separately quantified: loosely sorbed P (NH(4)Cl-P), iron-associated P (BD-P), calcium- bound P (HCl-P), metal oxide bound P (NaOH-P), and residual P (organic and refractory P). The results indicated that the fractional composition of the examined lakes was different while the total P concentrations were approached. The inorganic P in the surface sediment mainly consisted of Ca-P followed by Fe-P in Qarun Lake, while Al-P took the second order in Wadi El-Rayan lakes. The ranks order of the different P extracts were HCl-P > residual-P approximately NaOH-P > NH(4)Cl-P > BD-P and residual-P > NH(4)Cl-P > HCl-P > NaOH-P > BD-P for Qarun and Wadi El-Rayan lakes, respectively.
authors.affiliation: Inland Water and Aquaculture Branch, National Institute of Oceanography and Fisheries, 101 Kasr El Aini St., Cairo, Egypt. abdelsatarmena@yahoo.com
authors.forename: Amaal Mansour
authors.initials: AM
authors.lastname: Abdel-Satar
authors.forename: Mohsen F
authors.initials: MF
authors.lastname: Sayed
mesh_terms: D005591:Chemical Fractionation; D004534:Egypt; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis* / Q000302:isolation & purification; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus