Solid-phase speciation studies of P have relied largely on the use of spectroscopic techniques, especially FTIR and NMR spectroscopies. In spite of the large amount of literature devoted to this subject, studies addressing P sorption mechanisms, particularly on goethite, have resulted in countless conflicting interpretations of binding mechanisms. EXAFS spectroscopy has been a remarkably useful technique to elucidate retention mechanisms of ions on mineral surfaces as it probes the local structural and electronic environment of an atom, therefore, providing detailed structural information, such as nearest neighbors, bond distance and coordination numbers. In our study, EXAFS spectroscopy was employed to assess the surface loading and pH effects on the surface structures forming at the surface of goethite at P concentrations below and at the P saturation ratio of goethite at different pHs, 3.0, 4.5 or 6.0. Our results showed a significant dependence of bonding configuration upon surface loading and changes in pH.

Surface loading and pH effects on phosphorus surface complexation at the goethite/water interface studied by extended X-ray absorption fine structure (EXAFS) spectroscopy

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.