Oxygen isotope fractionation in phosphate during iron oxide-phosphate interaction
EMSL Project ID
29411
Abstract
Measurements of 18O/16O ratio of organic and inorganic PO4 in laboratory experiments have found that microbial metabolism of PO4 is accompanied by specific oxygen isotope fractionations. More importantly, phosphate resists isotopic exchange and fractionation with water at low, near surface temperatures in non-biological, abiotic processes (<80oC). Until now, all reaction networks that involve P cycling in natural environments have been fully understood except important remaining puzzle: phosphate-iron oxides interactions. The primary goal of this project, therefore, is to complete this puzzle to develop a new application of PO4 oxygen isotope (18O/16O ratio i.e. δ18Op) with δ18O as biomarker and indicator of microbial activity in specific reaction pathway. The proposed research, therefore, will investigate the mineral transformation (ferrihydrite → goethite → hematite) at environmentally relevant conditions using Mössbauer spectroscopy. This information will be vital to understand the kinetic and equilibrium oxygen isotope fractionation of phosphate during its sorption/desorption on iron oxide
Project Details
Project type
Exploratory Research
Start Date
2008-06-09
End Date
2009-06-14
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Jaisi, D.P. Blake, R.E., Kukkadapu, R. Fractionation of oxygen isotopes in phosphate during its sorption/desorption to iron oxides (Submitted: Geochimica et Cosmochima Acta).
Jaisi, D.P., Blake, R.E., Kukkadapu, R.K. Fractionation of oxygen isotopes in phosphate during its interactions with iron oxides. Geochimica et Cosmochimica Acta 74 (2010) 1309?1319