Using
wastewater as fertilizer
Research
News Aug 01, 2012
Sewage
sludge, wastewater and liquid manure are valuable sources of fertilizer for
food production. Fraunhofer researchers have now developed a chemical-free,
eco-friendly process that enables the recovered salts to be converted directly
into organic food for crop plants.
Phosphorus
is a vital element not only for plants but also for all living organisms. In
recent times, however, farmers have been faced with a growing shortage of this
essential mineral, and the price of phosphate-based fertilizers has been
steadily increasing. It is therefore high time to start looking for
alternatives. This is not an easy task, because phosphorus cannot be replaced
by any other substance. But researchers at the Fraunhofer Institute for
Interfacial Engineering and Biotechnology IGB in Stuttgart have found a
solution that makes use of locally available resources which, as unlikely as it
might seem, are to be found in plentiful supply in the wastewater from sewage
treatment plants and in the fermentation residues from biogas plants: a perfect
example of the old saying “from muck to riches”. The new process was developed
by a team of scientists led by Jennifer Bilbao, who manages the nutrient
management research group at the IGB. “Our process precipitates out the
nutrients in a form that enables them to be directly applied as fertilizer,”
she explains.
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