New perspectives on arsenic speciation and fate in anoxic aqueous environments: Resolving unexplored interactions with the sulfur cycle. Using exciting new experiments and innovative analyses, this project will provide transformational insights into how sulfur cycling in the Earth’s critical zone affects arsenic speciation and fate. The project will resolve, for the first time, unexplored interactions between arsenic geochemistry and the low-temperature formation and transformation of metastable ....New perspectives on arsenic speciation and fate in anoxic aqueous environments: Resolving unexplored interactions with the sulfur cycle. Using exciting new experiments and innovative analyses, this project will provide transformational insights into how sulfur cycling in the Earth’s critical zone affects arsenic speciation and fate. The project will resolve, for the first time, unexplored interactions between arsenic geochemistry and the low-temperature formation and transformation of metastable iron sulfide minerals. The outcomes will provide crucially important new perspectives on arsenic geochemistry in anoxic soils, sediments and groundwater systems.Read moreRead less
Interactions between antimony and the sulphur cycle. This project aims to unravel unexplored interactions between the sulphur cycle and fundamentally important aspects of antimony geochemistry in the Earth’s critical zone. This project will resolve interactions between antimony geochemistry and the low-temperature formation and transformation of metastable iron sulphide minerals. The outcomes are expected to provide crucially important perspectives on antimony geochemistry in anoxic soils, sedim ....Interactions between antimony and the sulphur cycle. This project aims to unravel unexplored interactions between the sulphur cycle and fundamentally important aspects of antimony geochemistry in the Earth’s critical zone. This project will resolve interactions between antimony geochemistry and the low-temperature formation and transformation of metastable iron sulphide minerals. The outcomes are expected to provide crucially important perspectives on antimony geochemistry in anoxic soils, sediments and groundwater systems. This understanding should lead to more accurate geochemical risk assessments and better site treatment strategies for environmental antimony contamination.Read moreRead less
Reactive oxygen species production on oxygenation of subsurface sediments. This project aims to examine the nature, extent and effect of redox processes in subsurface environments. Reactive oxygen species, including hydrogen peroxide, superoxide and hydroxyl radicals, transform and affect redox-active substances in the environment such as arsenic, uranium and natural organic matter (which may be oxidised to carbon dioxide). Production of significant quantities of reactive oxygen species on oxyge ....Reactive oxygen species production on oxygenation of subsurface sediments. This project aims to examine the nature, extent and effect of redox processes in subsurface environments. Reactive oxygen species, including hydrogen peroxide, superoxide and hydroxyl radicals, transform and affect redox-active substances in the environment such as arsenic, uranium and natural organic matter (which may be oxidised to carbon dioxide). Production of significant quantities of reactive oxygen species on oxygenation of subsurface sediments through actions such as aquifer recharge and high flow events may alter the form and mobility of trace elements and influence the cycling of carbon and eventual efflux of carbon dioxide to the atmosphere. This project will examine the nature, extent and effect of these redox processes in selected subsurface environments. This research could have implications for contaminant transformation and fate and carbon cycling.Read moreRead less
Maximising carbon sequestration in freshwater wetlands. Maximising carbon sequestration in freshwater wetlands. This project aims to determine how manipulation of wetland hydrology can alter sulphur and iron cycling to inhibit methane emission and improve wetland net-carbon sequestration. Wetlands are among earth's most efficient ecosystems for carbon sequestration, but methane emission can offset this capacity. Redox cycling of sulphur and iron in wetlands can inhibit methane emission, but the ....Maximising carbon sequestration in freshwater wetlands. Maximising carbon sequestration in freshwater wetlands. This project aims to determine how manipulation of wetland hydrology can alter sulphur and iron cycling to inhibit methane emission and improve wetland net-carbon sequestration. Wetlands are among earth's most efficient ecosystems for carbon sequestration, but methane emission can offset this capacity. Redox cycling of sulphur and iron in wetlands can inhibit methane emission, but the precise biogeochemical processes and their efficiency are very poorly constrained due to a lack of studies—especially in Australian freshwater wetlands. This project is expected to inhibit methane emission in freshwater wetlands and maximise their net carbon sequestration efficiency.Read moreRead less
Unraveling hexavalent chromium formation and fate in fire-impacted soil. Hexavalent chromium is a cancer-causing toxin. It can form via heating of natural (unpolluted) soil during bushfires. However, little is known of the processes and factors which govern its formation and behavior in fire-impacted soil. Using a combination of field-based investigations, innovative experiments and cutting edge analytical approaches, this project aims to systematically explore hexavalent chromium formation vi ....Unraveling hexavalent chromium formation and fate in fire-impacted soil. Hexavalent chromium is a cancer-causing toxin. It can form via heating of natural (unpolluted) soil during bushfires. However, little is known of the processes and factors which govern its formation and behavior in fire-impacted soil. Using a combination of field-based investigations, innovative experiments and cutting edge analytical approaches, this project aims to systematically explore hexavalent chromium formation via fire-induced heating of soil and to examine its post-fire fate in soil systems. The results will transform our understanding of the chromium cycle at the Earth’s surface, and will facilitate accurate assessment and mitigation of the risks posed by hexavalent chromium formation in fire-impacted soil.Read moreRead less
Antimony geochemistry and Earth's dynamic near-surface iron cycle. This project aims to advance our fundamental understanding on the geochemistry of antimony – a critical mineral resource and environmental pollutant of growing concern. This will be achieved by pioneering an innovative combination of advanced synchrotron-based tools and sophisticated isotopic approaches to unravel important interactions between antimony geochemistry and the iron cycle in soils, sediments and aquatic systems. The ....Antimony geochemistry and Earth's dynamic near-surface iron cycle. This project aims to advance our fundamental understanding on the geochemistry of antimony – a critical mineral resource and environmental pollutant of growing concern. This will be achieved by pioneering an innovative combination of advanced synchrotron-based tools and sophisticated isotopic approaches to unravel important interactions between antimony geochemistry and the iron cycle in soils, sediments and aquatic systems. The expected outcomes will provide novel insights into refined strategies to manipulate coupling between antimony mobility and iron cycling for improved rehabilitation of degraded landscapes, safe disposal of hazardous wastes and sustainable exploitation of Australia’s valuable antimony reserves.Read moreRead less
Redox transformations of natural organic matter. This project aims to determine the electron transfer (redox) properties of terrestrially and microbially-derived natural organic matter (NOM) and the implications of these redox characteristics to reactive oxygen species generation, metals transformation and carbon cycling. Experimental and computational studies using model compounds containing quinone and thiol-containing functional groups as well as well-characterised humic substances and algal ....Redox transformations of natural organic matter. This project aims to determine the electron transfer (redox) properties of terrestrially and microbially-derived natural organic matter (NOM) and the implications of these redox characteristics to reactive oxygen species generation, metals transformation and carbon cycling. Experimental and computational studies using model compounds containing quinone and thiol-containing functional groups as well as well-characterised humic substances and algal exudates will be undertaken under both dark and light conditions. Kinetic models of these processes will be developed enabling prediction of the impact of NOM-mediated electron transfer processes on oxidant generation, metals transformation and carbon cycling.Read moreRead less
Resolving the role of dryland flooding in the global carbon cycle. Aquatic sources of carbon dioxide and methane are globally significant, but unknown for flooded drylands. The aim of this project is to use an innovative combination of well-integrated methodologies to determine if flooded drylands release large amounts of carbon dioxide and methane. This project is significant because this release of carbon dioxide and methane has not previously been accounted for and may change the magnitude of ....Resolving the role of dryland flooding in the global carbon cycle. Aquatic sources of carbon dioxide and methane are globally significant, but unknown for flooded drylands. The aim of this project is to use an innovative combination of well-integrated methodologies to determine if flooded drylands release large amounts of carbon dioxide and methane. This project is significant because this release of carbon dioxide and methane has not previously been accounted for and may change the magnitude of the global terrestrial carbon dioxide sink and account of some of the planet’s missing sources of methane. The outcomes of this project will make a significant contribution to our understanding of the global carbon cycle and earth climate system, and inform future management of these systems.
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Discovery Early Career Researcher Award - Grant ID: DE140100056
Funder
Australian Research Council
Funding Amount
$392,290.00
Summary
In situ measurements to investigate the mobilisation and speciation of emerging and priority oxyanionic contaminants in water, sediment, and soil. Emerging and priority oxyanionic contaminants such as antimony, chromium, vanadium and tungsten present a significant environmental hazard. They are often associated with mining, and numerous contaminated sites have been identified within Australia. In order to manage these contaminants appropriately, there needs to be suitable methods to analyse them ....In situ measurements to investigate the mobilisation and speciation of emerging and priority oxyanionic contaminants in water, sediment, and soil. Emerging and priority oxyanionic contaminants such as antimony, chromium, vanadium and tungsten present a significant environmental hazard. They are often associated with mining, and numerous contaminated sites have been identified within Australia. In order to manage these contaminants appropriately, there needs to be suitable methods to analyse them. Passive sampling technology will be developed that will allow the measurement of these contaminants and their speciation in water, and sediment and soil pore waters. This project will use these new samplers to investigate the geochemical mechanisms of mobilisation of these contaminants in laboratory mesocosm experiments, as well as at selected contaminated field sites within Australia.Read moreRead less
Untangling metabolism and greenhouse gas production in intermittent streams. Freshwater streams are disproportionately large producers of greenhouse gases. Identifying the factors controlling their greenhouse gas production is critical as stream function is increasingly altered by both changing rainfall patterns and human pollution. This project aims to resolve the factors controlling stream greenhouse gas production. It will apply an unprecedented combination of continuous stream function and i ....Untangling metabolism and greenhouse gas production in intermittent streams. Freshwater streams are disproportionately large producers of greenhouse gases. Identifying the factors controlling their greenhouse gas production is critical as stream function is increasingly altered by both changing rainfall patterns and human pollution. This project aims to resolve the factors controlling stream greenhouse gas production. It will apply an unprecedented combination of continuous stream function and intensive isotope measurements to perennially flowing and intermittent streams in disturbed and undisturbed landscapes. This project is significant because it will quantify the changing role of streams in greenhouse gas emissions. Outcomes will provide critical information for managing Australia’s freshwater resources. Read moreRead less