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
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
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
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
Groundwater organic matter: carbon source or sink? The contribution of organic matter in groundwater to the global terrestrial carbon budget is unknown. This project aims to determine the processes that control the amount of groundwater organic matter by using six research bore-fields and laboratory facilities to analyse the concentration and character of both dissolved and colloidal organic matter. This is designed to determine the rate and extent of both the biological and the physiochemical p ....Groundwater organic matter: carbon source or sink? The contribution of organic matter in groundwater to the global terrestrial carbon budget is unknown. This project aims to determine the processes that control the amount of groundwater organic matter by using six research bore-fields and laboratory facilities to analyse the concentration and character of both dissolved and colloidal organic matter. This is designed to determine the rate and extent of both the biological and the physiochemical processes determining groundwater organic matter concentration. By quantifying the environmental conditions under which groundwater is a carbon source or sink, the project could guide policy to enable the management of the groundwater resource as part of the carbon economy.Read moreRead less
To what extent does fire affect karst processes? Burning questions for fire management. Fire management is of crucial importance for both asset protection and ecosystem management. However, the effects of fire in karst systems is poorly understood. This project will undertake experiments to determine the effects of fire on surface and subsurface processes, including stalagmite formation, that can be used to improve fire management policy.