HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Novak, J. M. Articles by Watts, D. W. Search for Related Content PubMed PubMed Citation Articles by Novak, J. M. Articles by Watts, D. W. Agricola Articles by Novak, J. M. Articles by Watts, D. W. Related Collections Surface Water Quality Watershed and Landscape Processes

Phosphorus Sorption by Sediments in a Southeastern Coastal Plain In-Stream Wetland

USDA-ARS-Coastal Plains Soil, Water and Plant Research Center, 2611 West Lucas St., Florence, SC 29501

^* Corresponding author (novak{at}florence.ars.usda.gov)

Received for publication February 21, 2006. A close relationship has been reported between sediment organic C (SedOC) content and its P sorption capacity (P_max) 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 P_max and TP concentrations, and (ii) to ascertain the role of both organically complexed and oxalate-extractable cations on the sediment P_max and TP values. The sediment's oxalate-extractable Fe (Fe_ox) and Al (Al_ox) contents were determined using acidified ammonium oxalate, while sodium pyrophosphate was used to extract organically complexed cations (Al_pryo, Ca_pyro, Fe_pyro, Mg_pyro, and Mn_pyro). Both the sediment's P_max and TP contents were strongly correlated with its SedOC concentration (r² > 0.90, P < 0.001). Only the Al_ox contents were significantly correlated with TP and P_max, 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 Al_pyro accounted for 88% of the variation in sediment P_max values, whereas a combination of Al_pyro and Ca_pyro 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 P_max 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.

Abbreviations: Al_ox, oxalate-extractable aluminum • Fe_ox, oxalate-extractable iron • OC, organic carbon • P_max, phosphorus sorption maxima • SedOC, sediment organic carbon • TP, total phosphorus