At the University of Sydney, an enthusiastic research team have been working on scaling up a plasma bubble column, originally with the aim of a one step process for the destruction of PFAS carried in an aqueous stream.

PFAS are a class of synthetic organofluorine compounds found in a range of consumer and industrial products and since the 1970’s they are most commonly found in AFFF firefighting foams. In addition to their environmental persistence (earning the name of “forever chemicals”), these compounds also bioaccumulate and are linked to cancers and a range of health irregularities in humans due to exposure. While AFFF foams are being phased out globally, legacy PFAS are highly soluble and mobile and are found in soil, surface water and ground water. A range of technologies exist for the treatment and remediation of this widespread pollutant with the objective of immobilizing PFAS or elimination i.e. capturing and adequately destroying these compounds.

Current remediation practices for contaminated sites focus on removing the PFAS by adsorbing the molecules onto either granular activated carbon or ion exchange resin and the contaminant is concentrated into a low volume waste subjected to high-temperature incineration for destruction.  In addition to transportation costs, high-temperature incineration is energy intensive producing greenhouse emissions and air pollutants. Other forms of high temperature destruction such as the plasma-arc furnace are equally effective but significantly more expensive.

This talk will describe the research team’s progress to date, focusing on increases in scale and reductions in energy costs that come from understanding the bubbly flow and the plasma on the process of PFAS destruction. The process is well suited to hard water and low to mid-strength PFAS contaminated water. This is an exciting example of Australian research using novel technology with genuine prospects of offering a viable solution to cleaning up the environment and improving public health.