In situ imaging of interfacial precipitation of phosphate on goethite
Adsorption and subsequent immobilization of orthophosphate on iron oxides is of considerable importance in soil fertility and eutrophication studies. Here, in situ atomic force microscopy (AFM) has been used to probe the interaction of phosphate-bearing solutions with goethite, a-FeOOH, (010) cleava...
| Main Authors: | , , , , |
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| Format: | Journal Article |
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American Chemical Society
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/25511 |
| _version_ | 1848751729626054656 |
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| author | Wang, L. Putnis, Christine Ruiz-Agudo, E. Hövelmann, J. Putnis, Andrew |
| author_facet | Wang, L. Putnis, Christine Ruiz-Agudo, E. Hövelmann, J. Putnis, Andrew |
| author_sort | Wang, L. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Adsorption and subsequent immobilization of orthophosphate on iron oxides is of considerable importance in soil fertility and eutrophication studies. Here, in situ atomic force microscopy (AFM) has been used to probe the interaction of phosphate-bearing solutions with goethite, a-FeOOH, (010) cleavage surfaces. During the dissolution of goethite we observed simultaneous nucleation of nanoparticles (1.0-3.0 nm in height) of iron phosphate (Fe-P) phases at the earliest nucleation stages, subsequent aggregation to form secondary particles (about 6.0 nm in height) and layered precipitates under various pH values and ionic strengths relevant to acid soil solution conditions. The heterogeneous nucleation rates of Fe-P precipitates at phosphate concentrations ranging from 5.0 to 50.0 mM were quantitatively defined. Enhanced goethite dissolution in the presence of high concentration NaCl or AlCl<inf>3</inf> leads to a rapid increase in Fe-P nucleation rates, whereas low concentration MgCl<inf>2</inf> inhibits goethite dissolution, this in turn influences Fe-P nucleation. Moreover, kinetic data analyses show that low concentrations of citrate caused an increase in the nucleation rate of Fe-P phases. However, at higher concentrations of citrate, nucleation acceleration was reversed with much longer induction times to form Fe-P nuclei. These in situ observations may improve the mechanistic understanding of processes resulting in phosphate immobilization by goethite-rich acid soils in the presence of various inorganic and organic additive molecules. |
| first_indexed | 2025-11-14T07:57:21Z |
| format | Journal Article |
| id | curtin-20.500.11937-25511 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:57:21Z |
| publishDate | 2015 |
| publisher | American Chemical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-255112017-09-13T15:16:04Z In situ imaging of interfacial precipitation of phosphate on goethite Wang, L. Putnis, Christine Ruiz-Agudo, E. Hövelmann, J. Putnis, Andrew Adsorption and subsequent immobilization of orthophosphate on iron oxides is of considerable importance in soil fertility and eutrophication studies. Here, in situ atomic force microscopy (AFM) has been used to probe the interaction of phosphate-bearing solutions with goethite, a-FeOOH, (010) cleavage surfaces. During the dissolution of goethite we observed simultaneous nucleation of nanoparticles (1.0-3.0 nm in height) of iron phosphate (Fe-P) phases at the earliest nucleation stages, subsequent aggregation to form secondary particles (about 6.0 nm in height) and layered precipitates under various pH values and ionic strengths relevant to acid soil solution conditions. The heterogeneous nucleation rates of Fe-P precipitates at phosphate concentrations ranging from 5.0 to 50.0 mM were quantitatively defined. Enhanced goethite dissolution in the presence of high concentration NaCl or AlCl<inf>3</inf> leads to a rapid increase in Fe-P nucleation rates, whereas low concentration MgCl<inf>2</inf> inhibits goethite dissolution, this in turn influences Fe-P nucleation. Moreover, kinetic data analyses show that low concentrations of citrate caused an increase in the nucleation rate of Fe-P phases. However, at higher concentrations of citrate, nucleation acceleration was reversed with much longer induction times to form Fe-P nuclei. These in situ observations may improve the mechanistic understanding of processes resulting in phosphate immobilization by goethite-rich acid soils in the presence of various inorganic and organic additive molecules. 2015 Journal Article http://hdl.handle.net/20.500.11937/25511 10.1021/acs.est.5b00312 American Chemical Society restricted |
| spellingShingle | Wang, L. Putnis, Christine Ruiz-Agudo, E. Hövelmann, J. Putnis, Andrew In situ imaging of interfacial precipitation of phosphate on goethite |
| title | In situ imaging of interfacial precipitation of phosphate on goethite |
| title_full | In situ imaging of interfacial precipitation of phosphate on goethite |
| title_fullStr | In situ imaging of interfacial precipitation of phosphate on goethite |
| title_full_unstemmed | In situ imaging of interfacial precipitation of phosphate on goethite |
| title_short | In situ imaging of interfacial precipitation of phosphate on goethite |
| title_sort | in situ imaging of interfacial precipitation of phosphate on goethite |
| url | http://hdl.handle.net/20.500.11937/25511 |