Issue 11. 9 August 2010.pdf - UWA Staff - The University of Western ...

One man’s waste is
another man’s soil
by Science Communication student Caris Allen
Can caustic waste from mineral
processing be turned into healthy
soil?
The processing of alumina, from bauxite
rock, produces bauxite residue – a
barren red mud that is difficult to dispose
of. But UWA Professorial Fellow and
bauxite enthusiast Dr Martin Fey is
discovering a cost-effective, simple way
Kikuyu grass helps turn mining waste
into soil
to reclaim this waste and turn it into
plant-friendly soil.
wa’s alumina refineries produce 20
millions tonnes of residue each year,
which is disposed of at four alumina
plants in WA.
Dr Fey said the rehabilitation of these
disposal areas was a difficult process,
especially when trying to revegetate the
areas.
With the support of his research
sponsors, Alcoa World Alumina Australia
and BHP Billiton Worsley Alumina,
Dr Fey and his research team are looking
at ways to ameliorate the bauxite residue.
It is treated in three stages, and in all
stages natural acids counteract the
alkalinity of the residue. In the first stage
gypsum is added, which acts to lower
the pH by breathing carbon dioxide into
the residue. The second stage involves
leaching out the excess salt and adding
bacteria, which transforms fertiliser into
various acids. The third stage involves
growing Kikuyu grass which again
breathes carbon dioxide into the system.
Kikuyu grass is a relatively salt-tolerant
and fast growing species that is widely
grown in WA as a turf grass and a
grazing pasture. As Dr Fey explains, by
Dr Martin Fey
pre-treating the residue and growing
Kikuyu grass, it becomes more like a soil
and less like a waste product. “All we are
really doing is giving the bauxite residue
a head start.”
Dr Fey said Kikuyu grass was ideal as a
first-stage rehabilitator for bauxite residue
disposal areas because it produced large
amounts of organic matter. In
rehabilitating the land, the grass
transforms the residue to become more
soil-like and leads the way for planting
native species directly into the site.
Dr Fey believes their research has the
potential to reduce the impact WA’s
minerals industry has on its environment,
shortening the time needed to reclaim
the disposal areas. Initial results are to
be presented at the World Conference of
Soil Science in Brisbane this month.
“Ultimately it’s about affordability and
sustainability – finding efficient solutions
that will have a lasting effect,” he said.
Looking for fun …?
Get ready for your personal diary to
be filled with new friends and
events.
The uwa Staff Social Club will be
launched next month, with a target of
1,000 members.
One of the movers behind the new club,
University Protocol Officer Kim Brown,
said the idea came after she noticed
that, at the Vice-Chancellor’s Christmas
party, most staff were mixing only with
their immediate colleagues.
“We feel that people are not making the
most of being part of a very big and
very diverse group,” Kim said.
The staff sports day is one of the few opportunities for staff to have fun together:
the social club will change that
“When staff and graduate students
come from overseas or interstate, they
often don’t even know the person at the
end of the corridor, let alone anybody
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UWA NEWS 9 August 2010
the University of Western Australia