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Phosphorus Sorption by Sediments in a Southeastern Coastal Plain In-Stream Wetland
- A close relationship has been reported between sediment organic C (SedOC) content and its P sorption capacity (Pmax) and total P (TP) concentration. Phosphorus sorbed to organically complexed cations is a proposed explanation for this relationship. The objectives of this study were (i) to determine relationships between in-stream wetland SedOC content and both the sediment's Pmax and TP concentrations, and (ii) to ascertain the role of both organically complexed and oxalate-extractable cations on the sediment Pmax and TP values. The sediment's oxalate-extractable Fe (Feox) and Al (Alox) contents were determined using acidified ammonium oxalate, while sodium pyrophosphate was used to extract organically complexed cations (Alpryo, Capyro, Fepyro, Mgpyro, and Mnpyro). Both the sediment's Pmax and TP contents were strongly correlated with its SedOC concentration (r2 > 0.90, P < 0.001). Only the Alox contents were significantly correlated with TP and Pmax, suggesting that amorphous Al forms have an important role in P sorption. All five pyrophosphate-extracted cations were significantly correlated with SedOC contents. Regression analyses showed that the Alpyro accounted for 88% of the variation in sediment Pmax values, whereas a combination of Alpyro and Capyro accounted for 98% of the variation in sediment TP concentrations. Additionally, Al and Ca chelated by SedOC compounds also have an important role in P binding and indicate that a linkage exists between the wetlands SedOC and Pmax content and its ability to accumulate TP. This study identified that two different mechanisms have significant roles in regulating P sorption by sediments in a southeastern Coastal Plain in-stream wetland.
Novak, J.M. , Watts, D.W.
marine sediments , phosphorus , sorption , carbon , cations , wetlands , streams , aluminum , iron , binding capacity , pyrophosphates , regression analysis , physicochemical properties , chelation , wetland soils , North Carolina
- Includes references
- Journal of environmental quality 2006 Nov-Dec, v. 35, no. 6
Journal Articles, USDA Authors, Peer-Reviewed
- Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.