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
New perspectives on iron oxide transformations in oxic and anoxic aqueous environments: implications for iron bioavailability and contaminant mobility. Transformations in the form and reactivity of iron oxides in oxic and anoxic aqueous environments are considerably more dynamic than previously thought. This project will examine the nature and extent of these transformations and elucidate their impact on supply of iron to organisms and mobility of uranium and arsenic in groundwaters.
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
Unravelling the history of nitrogen cycling within the central Great Barrier Reef. This project aims to use coral skeleton geochemical analysis to establish if, when, and how nitrogen cycling changed along the central inshore region of the Great Barrier Reef (GBR) lagoon. Increasing anthropogenic nitrogen discharge to coastal waters could drive ecosystem decline in the GBR, one of Australia’s most sensitive and economically valuable natural environments. However, the full effect of anthropogenic ....Unravelling the history of nitrogen cycling within the central Great Barrier Reef. This project aims to use coral skeleton geochemical analysis to establish if, when, and how nitrogen cycling changed along the central inshore region of the Great Barrier Reef (GBR) lagoon. Increasing anthropogenic nitrogen discharge to coastal waters could drive ecosystem decline in the GBR, one of Australia’s most sensitive and economically valuable natural environments. However, the full effect of anthropogenic nitrogen is unclear due to a lack of long, continuous records. This project will unravel the history of nitrogen cycling in the GBR since the mid-1800s, knowledge crucial for managing this reef system.Read moreRead less
A new paradigm for the accumulation and persistence of metastable iron sulphides in sulphidic soils. Metastable iron sulphide minerals have a critical role in controlling surface- and ground-water quality. This project will transform our understanding of the environmental geochemistry of metastable iron sulphides in sulphidic soils. This will greatly enhance our ability to predict and manage water quality in a wide range of important aquatic systems.
Groundwater in the southeast Murray Basin: Developing an integrated hydrogeological model and predicting future changes. Agricultural and urban development increases demands on groundwater resources. The sustainable use of groundwater requires a thorough knowledge of hydrogeology. This project addresses the origins, age, and geochemical evolution of groundwater in the Murray Basin, in particular constraining groundwater flow patterns, aquifer-aquitard interaction, water-rock interaction, and gro ....Groundwater in the southeast Murray Basin: Developing an integrated hydrogeological model and predicting future changes. Agricultural and urban development increases demands on groundwater resources. The sustainable use of groundwater requires a thorough knowledge of hydrogeology. This project addresses the origins, age, and geochemical evolution of groundwater in the Murray Basin, in particular constraining groundwater flow patterns, aquifer-aquitard interaction, water-rock interaction, and groundwater-surface water interactions both under present day and previous climatic conditions. The results of this project will ensure that this groundwater resource can be more effectively used and managed sustainably over the long term. In particular, historical responses of the system will be used to predict the effects of landuse or climate changes.Read moreRead less
Biogeochemical drivers of uranium isotope fractionation in regolith and groundwater. Water and soil resources are critical to Australia's present and future health and wealth. This project provides necessary data to increase our understanding groundwater recharge, flow and quality, weathering rates and uranium behaviour in soil and water. It will help delineate the impacts of agricultural activities and climate change. It may also trigger the development of new mineral exploration strategies for ....Biogeochemical drivers of uranium isotope fractionation in regolith and groundwater. Water and soil resources are critical to Australia's present and future health and wealth. This project provides necessary data to increase our understanding groundwater recharge, flow and quality, weathering rates and uranium behaviour in soil and water. It will help delineate the impacts of agricultural activities and climate change. It may also trigger the development of new mineral exploration strategies for uranium and other commodities.Read moreRead less
Shallow water carbonate sediment dissolution in the global carbon cycle. Carbonate sediment dissolution is a globally significant process, but poorly understood in shallow marine waters. This project will determine whether the combined effect of organic matter, ocean acidification and pore water flow in shallow water carbonate sediments increases the release of calcium and alkalinity to the ocean. This project is significant because this release has not previously been accounted for and may lead ....Shallow water carbonate sediment dissolution in the global carbon cycle. Carbonate sediment dissolution is a globally significant process, but poorly understood in shallow marine waters. This project will determine whether the combined effect of organic matter, ocean acidification and pore water flow in shallow water carbonate sediments increases the release of calcium and alkalinity to the ocean. This project is significant because this release has not previously been accounted for and may lead to an additional uptake of atmospheric carbon dioxide into the global ocean, maybe some additional buffering against ocean acidification, but unfortunately, maybe also a loss of carbonate ecosystems. The outcomes of this project will make a significant contribution to our understanding of the global carbon cycle.
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