Water Industry News
From sewage sludge to
Wednesday, 18 January 2006
A picture of the
microbes that break down the sewage. The most important ones are
yellow. (photo:Damien Batstone)
Sewage isn’t one of the most popular
topics to talk about but studying sewage could be if you’re interested
in reducing greenhouse gases.
With the support of local councils on the
Sunshine Coast, the University of Queensland’s Advanced Wastewater
Management Centre is currently researching the potential to produce
electricity from sewage treatment waste.
Other Local Government councils around Australia have also undertaken
similar projects to test the transfer of energy from waste to electricity.
The Biosolids Re-use and Energy Production Project Study will develop
existing technology to enable a bioreactor to handle the supply of
biosolids, capture methane and produce electricity.
Director of the Advanced Wastewater Management Centre, Professor Yurg
Keller, says the technology is used worldwide but is constantly evolving.
“The method has been used for about 20 to 30 years in other areas but I
think there’s a change now because of the demand on getting more and
more nitrogen removal from the waste treatment process. This makes it more
and more difficult to get the energy out at the same time”.
Professor Keller’s research will also determine whether a centralised
treatment plant to convert sewage sludge is a cost effective option.
“Quite likely it will be… to combine all the waste sludges from the
various council treatment plants, transport them to the one place and
treat it in that place to gain the energy return and then dispose of the
sludge as we currently do”.
An added bonus, Professor Keller says, is that there will be much less
sludge to dispose of following the treatment process.
“We produce a lot of greenhouse gases because we use a lot of
electricity in these waste water treatment plants… So, what can we do to
reduce that greenhouse production?… The best way is to recover the
energy that’s in the waste material that we’re actually discharging
and that can offset the energy consumption and reduce greenhouse
The project will be completed mid-year after which the local councils will
decide on an option to best benefit the environment and the public.