Professor Mike Manefield established a team of researchers investigating the biological remediation of chlorinated solvents starting in 2004. The group has been funded by the University of New South Wales, Orica Australia Pty Ltd, Dow Chemicals Australia Pty Ltd, Coffey Environments and the Indo-Australia Biotechnology Fund. Dr Matthew Lee now does the heavy lifting in this portfolio.
Culture development and deployment
The major focus of the group is the development of mixed microbial consortia for augmentation of contaminated sites. We currently maintain fully characterised cultures for complete chloroform, 1,2-dichloroethane, dichloromethane and perchloroethene degradation in subsurface environments. These are the only cultures that can be deployed in Australia for chlorinated solvent degradation without quarantine approval. The group has extensive field experience and offers consulting services to industry including culture production and deployment services, quantification of specific bacterial groups in the environment and tracer testing. The technologies and expertise of the group have been made available through the commercial consulting platform Novorem Pty Ltd.
Fluorinated compounds such as PFOS and PFOA in fire fighting foams are emerging contaminants of concern now routinely detected in contaminated groundwater and soil globally. There are numerous examples at Defence Force bases and airports around Australia. We have recently secured ARC LP funding with Coffey as industry partner to identify and harvest microorganisms capable of directly or indirectly affecting PFOS or PFOA degradation in the environment. Understanding the role of microorganisms and the biogeochemical processes they perform in relation to fluorinated compounds will inform our handling of contaminated sites and lead to development of cost effective and sustainable remediation technologies.
Exploiting mixed biogeochemical processes
We have been investigating the manipulation of electron flow in the environment to accelerate the breakdown of chlorinated solvents in groundwater. At sites with mixtures of chlorinated solvents, one often inhibits the biodegradation of another. For five years we have investigated the application of soluble redox active compounds to catalyse electron transfer from reductants or bacteria to chlorinated solvents. More recently this has included the use of bacteria to generate iron and sulfur reductants in situ. These approaches harness the reducing power of many different bacteria in the environment rather than specific groups.
Activated carbon recycling technology
As part of the Environmental Biotechnology Cooperative Research Centre, we have invented and patented (PCT/AU2007/001848) a novel activated carbon recycling process that has clear advantages over existing technologies used for this purpose. The novel technology involves a cyanocobalamin augmented 90% ethanol solution that circulates through a zinc stock and the contaminated activated carbon sample. This simultaneously desorbs and reduces the contaminating organochlorins, resulting in pristine activated carbon that is suitable for re-use. The technology has been tested at bench scale and awaits interest from a commercialisation partner to conduct tests at pilot (x100) scale. Click here for a press release.