Transformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwater
Abstract In anoxic subsurface environments, low Fe(III) bioaccessibility greatly limits in situ biodegradation of petroleum hydrocarbons (PHCs). Ferric ammonium citrate is a soluble compound that has the potential to increase the bioaccessibility of Fe(III). However, in neutral to alkaline environme...
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2025-02-01
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| Series: | Geochemical Transactions |
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| Online Access: | https://doi.org/10.1186/s12932-025-00097-z |
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| author | Essouassi Elikem David Bulmer Kris Bradshaw Ardalan Hayatifar Matthew B. J. Lindsay Steven D. Siciliano Derek Peak |
| author_facet | Essouassi Elikem David Bulmer Kris Bradshaw Ardalan Hayatifar Matthew B. J. Lindsay Steven D. Siciliano Derek Peak |
| author_sort | Essouassi Elikem |
| collection | DOAJ |
| description | Abstract In anoxic subsurface environments, low Fe(III) bioaccessibility greatly limits in situ biodegradation of petroleum hydrocarbons (PHCs). Ferric ammonium citrate is a soluble compound that has the potential to increase the bioaccessibility of Fe(III). However, in neutral to alkaline environments, Fe(III) hydrolysis can produce Fe(III) (oxyhydr)oxides that may subsequently transform or recrystallize to relatively stable and less bioaccessible phases. Accordingly, the objective of this study was to elucidate the transformation and fate of Fe(III) contributed by ferric ammonium citrate in a gasoline-contaminated subsurface environment that was undergoing in situ bioremediation. Ferric ammonium citrate, together with sodium tripolyphosphate, magnesium sulphate, and nitric acid, was continuously injected into the contaminated groundwater for about 22 weeks. Colloids in the groundwater (solid particles retained on a 0.45 $$\upmu$$ μ m filter) and soil cores were collected from the site. Fe speciation in these samples was characterized using X-ray absorption near edge structure (XANES) and Fourier transform infrared (FTIR) spectroscopy. The groundwater colloids (GWCs) contained mostly octahedrally coordinated Fe(III), but the subsoils contained both octahedrally coordinated Fe(III) and Fe(II). The fraction of Fe(II) in the subsoils generally increased after about 22 weeks of continuous amendment injection. Ferric ammonium citrate did not persist in the PHC-contaminated subsurface: the Fe(III) it contained was transformed to solid phases. Fe(III)-organic-matter (Fe(III)-OM) complex/coprecipitate and sulfate green rust were the major phases present in the GWCs; akaganeite, chloride green rust, vivianite, ferrihydrite, Fe(III)-silicate, and magnetite were present as minor phases. The subsoils contained three major phases: Fe(III)-OM complex/coprecipitate, magnetite, and calcium ferric silicate. The presence of major Fe(II) phases in the subsoils strongly indicate that secondary Fe(III) phases (especially Fe(III)-OM complex/coprecipitate) served as terminal electron acceptors during the microbial degradation of PHCs in the contaminated subsurface. |
| format | Article |
| id | doaj-art-bca34b4b38174395b430bd77219b7661 |
| institution | Kabale University |
| issn | 1467-4866 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | BMC |
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| series | Geochemical Transactions |
| spelling | doaj-art-bca34b4b38174395b430bd77219b76612025-02-09T12:55:45ZengBMCGeochemical Transactions1467-48662025-02-0126111210.1186/s12932-025-00097-zTransformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwaterEssouassi Elikem0David Bulmer1Kris Bradshaw2Ardalan Hayatifar3Matthew B. J. Lindsay4Steven D. Siciliano5Derek Peak6Department of Chemistry, University of SaskatchewanDepartment of Soil Science, University of SaskatchewanFederated Cooperatives Ltd.Department of Geological Sciences, University of SaskatchewanDepartment of Geological Sciences, University of SaskatchewanDepartment of Soil Science, University of SaskatchewanDepartment of Soil Science, University of SaskatchewanAbstract In anoxic subsurface environments, low Fe(III) bioaccessibility greatly limits in situ biodegradation of petroleum hydrocarbons (PHCs). Ferric ammonium citrate is a soluble compound that has the potential to increase the bioaccessibility of Fe(III). However, in neutral to alkaline environments, Fe(III) hydrolysis can produce Fe(III) (oxyhydr)oxides that may subsequently transform or recrystallize to relatively stable and less bioaccessible phases. Accordingly, the objective of this study was to elucidate the transformation and fate of Fe(III) contributed by ferric ammonium citrate in a gasoline-contaminated subsurface environment that was undergoing in situ bioremediation. Ferric ammonium citrate, together with sodium tripolyphosphate, magnesium sulphate, and nitric acid, was continuously injected into the contaminated groundwater for about 22 weeks. Colloids in the groundwater (solid particles retained on a 0.45 $$\upmu$$ μ m filter) and soil cores were collected from the site. Fe speciation in these samples was characterized using X-ray absorption near edge structure (XANES) and Fourier transform infrared (FTIR) spectroscopy. The groundwater colloids (GWCs) contained mostly octahedrally coordinated Fe(III), but the subsoils contained both octahedrally coordinated Fe(III) and Fe(II). The fraction of Fe(II) in the subsoils generally increased after about 22 weeks of continuous amendment injection. Ferric ammonium citrate did not persist in the PHC-contaminated subsurface: the Fe(III) it contained was transformed to solid phases. Fe(III)-organic-matter (Fe(III)-OM) complex/coprecipitate and sulfate green rust were the major phases present in the GWCs; akaganeite, chloride green rust, vivianite, ferrihydrite, Fe(III)-silicate, and magnetite were present as minor phases. The subsoils contained three major phases: Fe(III)-OM complex/coprecipitate, magnetite, and calcium ferric silicate. The presence of major Fe(II) phases in the subsoils strongly indicate that secondary Fe(III) phases (especially Fe(III)-OM complex/coprecipitate) served as terminal electron acceptors during the microbial degradation of PHCs in the contaminated subsurface.https://doi.org/10.1186/s12932-025-00097-zIn situ bioremediationPetroleum hydrocarbonsFe(III) transformationXANES spectroscopy |
| spellingShingle | Essouassi Elikem David Bulmer Kris Bradshaw Ardalan Hayatifar Matthew B. J. Lindsay Steven D. Siciliano Derek Peak Transformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwater Geochemical Transactions In situ bioremediation Petroleum hydrocarbons Fe(III) transformation XANES spectroscopy |
| title | Transformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwater |
| title_full | Transformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwater |
| title_fullStr | Transformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwater |
| title_full_unstemmed | Transformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwater |
| title_short | Transformation and fate of Fe(III) in petroleum-hydrocarbon-contaminated soil and groundwater |
| title_sort | transformation and fate of fe iii in petroleum hydrocarbon contaminated soil and groundwater |
| topic | In situ bioremediation Petroleum hydrocarbons Fe(III) transformation XANES spectroscopy |
| url | https://doi.org/10.1186/s12932-025-00097-z |
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