Studies to stop toxic foam

sewageThe $420,000 project is based on work by Dr Daniel Tillett, a senior lecturer in the University’s School of Pharmacy and Applied Science.

It is supported by an Australian Research Council linkage grant announced last week by Science and Innovation Minister, Senator Kim Carr. Dr Tillett is a specialist in genomics, bioinformatics and DNA sequencing.

He says the system, developed in his Bendigo-based laboratory over the past three years, aims to recreate the right balance between ‘good’ and ‘bad’ bacteria in wastewater treatment plants by using natural ‘bacteriophages’ –  viruses that are predators of bacteria, but harmless to other organisms.

‘The aim is to prevent troublesome foaming, a common problem at sewage and wastewater treatment plants throughout Australia.  For example, one problem with foam is it can escape the plant and wash up on beaches where there is ocean outfall from sewage plants.’

Foaming is caused by a build up of ‘bad’ bacteria which Dr Tillett’s research has shown can be kept in check by these ‘bacteriophages’.

Foam is not only unsightly, but can be dangerous and difficult to remove. ‘We’ve had some foam samples survive in our lab for years,’ he says.

One of the dangers of foam comes from the harmful bacteria trapped in the foam bubbles. ‘These bacteria can damage the environment and infect animals and humans. Occasionally they can cause some very serious infections that are very difficult to treat.’

Dr Tillett says because wastewater treatment relies on settlement ponding, surface foaming creates significant and costly problems for the industry.

‘It can also be a safety issue as it makes it hazardous for workers who have to move around the plant because they can’t see where they are going and it can make walkways very slippery.’

From a biological point of view, Dr Tillett says sewage and wastewater treatment processes are just another ecosystem which, to work effectively, have to remain in balance. 

‘You can regard the bacteria that lead to foaming as ‘weeds’ in that they have overgrown their ecosystem.’

His research has identified bacteria phages that can act like ‘insects’ that specifically attack the ‘weed’ bacteria, keeping them in check and leaving the ‘good’ bacterial to treat the waste safely.

Dr Tillett says the process is not introducing any new organisms or genetically modified viruses into the waste stream as the phages are all natural isolates. 

The project is being carried out in association with the University of Melbourne, Melbourne Water Corporation, South Australian Water Corporation, and the Water Corporation of Western Australia.

For further information or interviews, please contact Dr Tillett on 03 5444 7361; or Ernest Raetz, Media Office, 0411 226 1919.