Photo: John Rayner
A freeze-thaw chamber at the Antarctic Division's Kingston headquarters is allowing researchers to test materials for use in remediation. Our research has shown that some clean-up techniques, such as bioremediation, work at low temperatures, although processes are slower. We know less about how materials respond during repeated freezing and thawing. For example, collaborative work undertaken with Macquarie University researcher, Dr. Damian Gore, has shown that controlled-release nutrients, commonly used in bioremediation, burst during repeated freeze-thaw. This means that the naturally occurring bacteria that we are trying to encourage to break down oil spills in Antarctica would feast and then starve, rather than enjoy the healthy diet that we know they really need.
Another material being tested is a mineral called zeolites. These unusual minerals have a cage-like structure and a useful and interesting surface. Collaborative work being done with Professor Geoff Stevens at the Melbourne University is focusing on developing these zeolite properties to be able to control reactions with nutrients, heavy metals and fuel spills. The idea is to incorporate successful zeolite material into Permeable Reaction Barriers. Testing at the moment in the freeze-thaw chamber is simulating 'top down freezing', as would occur in the field, to determine if this compound will behave structurally in the same way that it does in temperate regions.