Using waste-water as fertiliser

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.

However, researchers at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB in Stuttgart have found a solution. It makes use of locally available resources that, 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. Read the rest of the article