An innovative plant for drying sludge from waste water has been put into operation in Vienna, making a step towards recycling phosphorus.
Up until now, phosphorus from sewage sludge has not generally been reused, but this new technology takes the first step towards changing that trend, which will allow this resource to be used as fertilizer in agriculture.
Energy company Wien Energie is laying the groundwork for the mass use of phosphorus through recycling, making another big step towards a circular economy. From 2033, it will be legally mandatory to recycle phosphorus from ash in all municipal wastewater treatment plants.
The Simmeringer Haide plant in Vienna dries the sludge, which is then thermally treated. During combustion, harmful substances are destroyed, while phosphorus can be re-separated from the resulting ash for the production of fertilizers. Sludge consists of 96 percent water, and for its burning it is necessary to reduce the moisture level first.
“When talking about sustainability, few people think about phosphorus recycling from sewage sludge. However, we have the opportunity to reuse this valuable raw material,” said Karl Gruber, director of Wien Energie.
The use of phosphorus fertilizers in the 20th century significantly increased agricultural yields. However, since 2014, phosphorus has been classified as a critical raw material at the EU level. Most of the phosphorus is imported from third countries, mainly from North Africa, where exploitation sometimes causes significant environmental pollution.
Wien Energie is currently conducting pilot projects with industrial partners and is investigating the possibility of building its own plant for this purpose. The final capacity could meet the phosphorus needs in the food production sector for the entire population of Vienna and Lower Austria, according to a statement from the City of Vienna.
Energy portal
Source: energetskiportal.rs
