Media Release
August 8, 2005
Solar energy for wastewater treatment
Researchers at UniSA are developing a unique treatment for wastewater
that guarantees improved water quality over existing treatments without
relying on expensive chemicals.
Improving the quality of treated wastewater from sewage treatment plants
for reuse is becoming more important than ever in Australia due to
dwindling water resources, according to Dr Bo Jin, Director of UniSA’s
Water Environment Biotechnology Laboratory.
“The poor quality of treated wastewater has limited its use for
agriculture and aquaculture,” Dr Bo Jin said.
“The last stage of any water treatment is to remove micro-organisms.
Currently we use chlorine as the disinfectant but, even after treatment,
the water still contains organic compounds. Chlorine removes the
micro-organisms but reacts to the organic pollutants, producing
disinfection by-products that are biologically undegradable and toxic
and can’t be removed from the water. When transferred to the eco system,
they can cause serious health consequences if used in agriculture and
other industries.
“This growing problem is of particular concern to the United Nations,
where close attention is being paid internationally to organic
pollutants, which cannot be removed economically – but a solution is on
the way,” Dr Jin said.
UniSA researchers are developing a single stage treatment that can
remove biological and chemical contaminants in the treated wastewater
from sewage treatment plants.
The new solar nano-photocatalytic wastewater treatment process can
replace a chlorination disinfection step as a tertiary treatment process
to disinfect the micro-organisms and at the same time remove the organic
compounds, making the wastewater suitable as a water resource.
“Normally micro-organisms are used to break down large organic compounds
but, because these compounds are biologically undegradable, we have to
use another form of energy to break them down. Our energy comes from UV
sunlight in association with photocatalysts. Energy generated from the
photocatalyst cell reaction can kill micro-organisms and break down the
undegradable compounds, resulting in clean water that can be used for an
extended range of agriculture and aquatic uses – and it won’t damage the
eco system,” Dr Jin said.
“The other good news is that this treatment process will be very cost
effective because the solar photocatalysts can be recovered and reused.
They use cheap energy from the sun,” he said.
Dr Jin recently won a Federal Government Australian Research Council
Linkage Grant of $285,000, with additional financial commitment from
industry partner Australian Water Quality Centre, to further develop
this novel process, looking at water quality objectives of technical
reliability and economic and environmental sustainability.
Media contact
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Geraldine Hinter office (08) 8302 0963 mobile 0417 861 832 email geraldine.hinter@unisa.edu.au