Hannah Amrhein, Lena Fries, and Hanna Fries have found a new approach to recovering the valuable plant nutrient phosphorus from waste water. For this, they used electroflotation, a process in which tiny flakes bind phosphates and transport them to the surface when voltage is applied to sheet metals. In the laboratory, they were able to bind nearly all the phosphate from a sample solution. The phosphate can then be converted into phosphoric acid or phosphates that are once again available for plants. Electroflotation is more effective than conventional precipitation processes. Waste water treatment plants recover only 40–60% of the phosphorus with common precipitation – but over 80% with electroflotation. The method still has to prove itself under waste water treatment plant conditions.
Hanna Maria Fries
Lena Maria Fries