The effects of drying on phosphorus sorption and speciation in subtropical river sediments

Kerr, Jason G., Burford, Michele, Olley, Jon and Udy, James (2010) The effects of drying on phosphorus sorption and speciation in subtropical river sediments. Marine and Freshwater Research, 61 8: 928-935. doi:10.1071/MF09124

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads

Author Kerr, Jason G.
Burford, Michele
Olley, Jon
Udy, James
Title The effects of drying on phosphorus sorption and speciation in subtropical river sediments
Journal name Marine and Freshwater Research   Check publisher's open access policy
ISSN 1323-1650
Publication date 2010-08
Sub-type Article (original research)
DOI 10.1071/MF09124
Volume 61
Issue 8
Start page 928
End page 935
Total pages 8
Editor A. J. Boulton
Place of publication Collingwood, VIC, Australia
Publisher CSIRO Publishing
Collection year 2011
Language eng
Formatted abstract
The present study investigated whether drying and desiccation substantially increase the biologically available phosphorus (P) in riverbed sediments from a dry subtropical river. Sequential extraction and batch equilibrium experiments were undertaken on sediments with contrasting organic matter content, percentage fines and P content. The response of sediments to drying differed predominately as a result of drying time rather than as a result of the different physiochemical properties and total P content of the sediments. For both in situ and laboratory drying, major changes in P speciation occurred in the surface-layer sediment (0–2 cm) where NH4Cl-P (loosely sorbed P) was higher in partially dried and desiccated sediments than in wet sediments. Conversely, NaOH-nrP (labile organic and poly-P) was significantly lower (P < 0.05) in partially dried and desiccated sediments than in wet sediments, suggesting that a substantial transformation from a relatively unavailable organic form to a readily available inorganic form of P had occurred with drying. The equilibrium phosphate concentration (EPC0), which is a measure of the potential for sediments to function as a source or a sink of phosphate (PO43–), was higher in sediments desiccated in situ and in the laboratory than in submerged and partially dried sediments. Together with the speciation results, the higher EPC0 indicates that the potential for sediments to release P during the next flow event is substantially increased as a result of desiccation. The lower EPC0 in partially dried sediments suggested that the degree of drying may be an important factor in terms of the long-term potential for sediments to act as a source or a sink of PO43– after rewetting. The results from the present study have important implications because natural or anthropogenic processes which lead to riverbed drying may increase the flux of bioavailable P from bed sediments when flow returns.
© CSIRO 2010
Keyword Desiccation
Soluble P
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Civil Engineering Publications
Official 2011 Collection
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 12 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 12 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Thu, 24 Mar 2011, 14:02:56 EST by Jeannette Watson on behalf of School of Civil Engineering