Phosphorus recovery and recycling - closing the loop

There is a clear and pressing need to better manage our planet's resources. Phosphorus is a crucial element for life, but the natural phosphorus cycle has been perturbed to such an extent that humanity faces two dovetailing problems: the dwindling supply of phosphate rock as a resource, and the overabundance of phosphate in water systems leading to eutrophication. This Tutorial Review will explore the current routes to industrial phosphorus compounds, and innovative academic routes towards accessing these same products in a more sustainable manner. It will then describe the many ways that useful phosphate can be recovered from waste streams, and how it can be recycled and used as a resource for new products. Finally, we will briefly discuss the barriers that have thus far prevented the widespread adoption of these technologies, and how we can close the loop to establish a modern phosphorus cycle.