Contaminant transformation in the environment
Once introduced into the environment, most contaminants undergo transformations that modify their fate and the risks they pose to aquatic organisms.
Biogeochemical processes are complex and are influenced by the composition of the environmental media (e.g. water, sediment and soil properties), and external processes (e.g. rainfall, temperature, pressure).
The concentrations and speciation of contaminants can change rapidly once sampled from the environment, and this often confounds the assessment of the risks that exist at field sites.
The bioavailability and toxicity of contaminants is usually speciation dependent, and knowledge of the rate of transformation from one chemical form to another is necessary to assess the risk to organisms following exposure to contaminants.
Complex experiments designed to study contaminant fate
We design and undertake complex experiments to determine how environmental conditions and processes alter the concentrations and forms of contaminants in surface and subsurface environments.
We maintain, modify and build experimental systems for studying contaminant transformations in environmental media, including:
- Deep-sea environments (subject to darkness, cold temperatures and high pressures)
- Deep-groundwater environments (such as those where coal and shale seams undergo fracking)
- Climate extremes (polar to tropical environments)
- Water treatment processes (e.g. chlorination systems and risks from discharges)
We study how contaminant fluxes from sediments are modified by sediment properties and water conditions, and design experimental systems that enable organism exposures to be assessed and test systems to be matched to environmental conditions predicted at assessments sites.
We are studying how organism exposure and toxicity is influenced by the exposure time of specific contaminants and complex mixtures, and utilising this knowledge to develop new methods for risk assessment, including:
- How guideline values are applied to episodic discharges of effluents
- How fluxes of contaminants from sediments are best determined to assess organism exposure risks
- How interactions between multiple stressors, such as nutrients, metals and hydrocarbons, influence toxicity and risk assessment outcomes
Providing answers to complex contaminant fate and exposure problems for industry and government
We are responsive and act to provide timely and reliable advice and testing necessary to provide answers to complex assessment questions.