Urgent action is needed to reduce the rate of phosphorus depletion said The Chartered Institution of Water and Environmental Management (CIWEM) in its latest policy statement.
The statement outlines the main issues relating to the world’s supply of useable phosphate and highlights the need for urgent action to achieve its recovery to improve food security and reduce geopolitical risk.
Phosphate is essential for all living cells; it is a part of all DNA and cells’ energy cycles. It is also the least abundant of the major plant nutrients. For phosphate there can be neither substitute nor replacement.
We rely on the mining of inorganic phosphates for agriculture and industry. This would not be an issue if there were abundant supplies, but that is far from the case.
At the present rate of extraction, today’s phosphate mines will be exhausted by the end of the 21st century and estimates of future reserves range from 200 to 400 years (at the current rate of extraction). China and the USA have both tried to implement measures to reduce exports of phosphate as they have already realised its strategic importance.
However whilst the future may sound bleak, wastewater treatment could recover 95% of the phosphate from urban wastewater. CIWEM believes land application of suitably treated biosolids (sewage sludge) is invariably the best way to conserve and recycle the phosphate it contains. Currently only 20% of the phosphate in urban wastewater in the EU is recycled. In order to increase this, CIWEM calls on all governments to follow the examples of Sweden and Germany and make phosphate recovery from urban wastewater a legal requirement.
“Phosphorus is scarce and resources are being depleted rapidly. To date, attention has focussed on removing phosphate from wastewater streams to prevent the eutrophication of waters" said Nick Reeves, CIWEM's Executive Director.
"But phosphate is of huge strategic value over the longer term and we must also act to recover phosphate from waste-streams for use. The economics of extensive phosphate recovery from wastewater would be quite favourable if we viewed phosphorus as a resource, rather than the conventional approach of treating it as a pollutant in the environment, and mining it in mineral form to fertilise our crops.”