Phosphorus recovery : new approaches to extending the life cycle

In may 2011 phosphorus was considered alongside lithium, neodynium, and rare earth metals as a potentially strategically important element. Phosphorus, a key element in plant growth (and thus in agriculture), is nonrenewable, obtained for commercial fertilizers from phosphate rock that is mined in a comparatively limited number of sites around the world. Debate swirls around the possibility that viable supplies of this rock will ultimately be exhausted, creating shortages that could devastate global agricultural output and lead to widespread hunger. Yet the threat posed by phosphorus scarcity contrasts sharply with the current environmental problems created by excessive amounts of the stuff in many places. As a nutrient, this element contributes significantly to algal blooms in waters fed by fertilizer and wastewater runoff. Several new technologies are exploring solutions to limit this impact through recovery or recycling. [authors abstract]