EU-funded project seeks to recover phosphorus from municipal sewage

Researchers from an EU-funded project sought to promote the recovery of phosphorus from municipal sewage, said the European Commission in a press release on Tuesday.

Phosphorus, which is excreted in urine, is a nutrient needed by all life. Plants extract phosphorus from soil; farmers replenish it via fertilizers.

To make the fertilizers and animal feed, the EU depends on imports of phosphorus, as about 90 percent of the demand, some 975,000 tons annually, is imported mainly from North Africa and the Middle East, where it is mined from phosphorus rock.

EU researchers found that this dependence could be reduced by recycling phosphorus from sewage sludge, the thick semi-solid material left over after treating municipal wastewater.

Recovered phosphorus from this sludge could theoretically cover about 20 percent of Europe's current demand, said project coordinator of P-REX Christian Kabbe of Kompetenzzentrum Wasser Berlin in Germany.

P-REX, which would end this month, was advancing that process by evaluating the costs and benefits of 10 currently promising technologies to recover phosphorus from sludge, or from the ashes left over from its incineration.

Alongside market analysis, P-REX would also produce a guidance document for policymakers and industry, outlining the suitable phosphorus recovery options and recommendations for fostering a European market for products containing recovered phosphorus, such as fertilizer.

In 2010, some 42 percent of Europe's municipal sewage sludge was treated and used on farmland, 27 percent was incinerated, 14 percent was disposed of by land filling and about 17 percent was disposed of in other ways, according to Eurostat.

But there are wide variations across Europe -- and even between regions -- in how each country currently treats and disposes sludge. The P-REX recommendations are tailored to these differences.

"The aim is not to change the modes, but recommend suitable recovery technology based on the infrastructure already in place," explained Kabbe.

But there would be no recycling without a market, which is dependent on price, quantity, handling, distribution, and the operational benefits of recovering phosphorus from sludge, said Kabbe.

"We know a lot about the technologies and how recycling phosphorus could work, but now we need to do the obvious and take action," he adds, "industry needs incentives, such as reasonable subsidies and EU-wide policies, to reach the economies of scale needed to reduce our dependence on imports."

Currently, only about 2,000 to 3,000 tons of struvite, a phosphorus-rich mineral, is produced each year in Europe from municipal sewage, said Kabbe. It represents the lowest hanging fruit and to increase this, the project launched an online platform in January 2015 to link European suppliers of recovered phosphorus with potential buyers.

The results of the project would be disseminated at international workshops and regional events to encourage more production.

"P-REX will provide an essential milestone for our future development into a recycling society," said Kabbe. Endit