PARAGRAPHPhosphorus has always been both a curse and a blessing. On the one hand, it is essential for all life forms and cannot be replaced by anything. On the other hand, wastewater treatment aims to minimize phosphorus concentrations in wastewater in order to minimize its discharge into rivers and lakes, where eutrophication caused by high phosphorus concentrations would lead to excessive plant growth. Phosphorus is extracted from rock phosphate deposits, which are finite and non-renewable. And as the issue of resource conservation is the focus of attention worldwide, phosphorus must be used sustainably.