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Adsorption of Phosphorus by Lake Sediment
Author(s) -
Harter Robert D.
Publication year - 1968
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1968.03615995003200040027x
Subject(s) - sediment , adsorption , phosphorus , sorption , eutrophication , phosphate , extraction (chemistry) , algae , chemistry , fraction (chemistry) , environmental chemistry , mineralogy , geology , nutrient , chromatography , botany , organic chemistry , paleontology , biology
The sediment of an eutrophic lake is capable of adsorbing a large amount of phosphorus from the water. To study the sorption mechanism, between 0 and 2.2 mg P was added to 0.1‐g sediment samples (1:50 sediment‐solution ratio). After equilibrium had been established, P remaining in solution was determined, and adsorbed P was extracted with 0.5 N NH 4 F and 0.1 N NaOH. Whereas all P adsorbed into the NaOH‐extractable fraction appeared to occur as an iron phosphate, NH 4 F apparently extracted P bonded by two different mechanisms. When less than about 0.1 mg P was added, NH 4 F extracted a tightly bonded form of P, probably occurring as an aluminum phosphate. When more than 0.1 mg P was added, additional P in a more loosely bonded form was adsorbed into the NH 4 F‐extractable fraction. The loosely bonded P appeared to be independent of Al content of the sediment, and could be removed by successive water extraction. The capability of the sediment to adsorb considerable loosely bonded P means that large influxes of P into the lake may be held temporarily and subsequently released to growing plants and algae.