Phosphorus is an indispensable raw material – not only for agriculture. At the same time, phosphorus is a finite resource classified as critical by the EU. Recovering the large amounts of phosphorus contained in wastewater is therefore an essential building block on the path to sustainable resource management.

Germany has set itself ambitious targets in this regard as part of the 2017 Sewage Sludge Ordinance and now faces the challenge of implementing the obligation to recover or recycle phosphorus as stipulated in the ordinance from 2029 onwards.

Today, more than 80% of sewage sludge is already incinerated, and this figure is rising. Sewage sludge, which has previously been co-incinerated in coal-fired power stations, for example, will in future mainly be sent to newly built sewage sludge incineration plants. Thermal pre-treatment with subsequent phosphorus recovery from sewage sludge incineration ash will therefore play a central role. However, studies predict that by 2029, phosphorus recovery techniques will only be available for approximately 30% of the sewage sludge ash produced.              
The Sewage Sludge Ordinance has provided for an "alternative" in this case, namely, to store sewage sludge ash temporarily for a transitional period and to carry out phosphorus recovery from the ash at a later date. However, it is becoming increasingly clear that the capacities required for recoverable temporary storage will also not be available to a sufficient extent for technical and legal reasons.

As a result, many experts now doubt whether the conditions for implementing the phosphorus recovery obligation within the framework specified by the Sewage Sludge Ordinance can be created in the remaining three years. Initial calls are being made to adapt the legal framework.

Against this background, experts will highlight the following aspects, among others, in their presentations and panel discussion during this session: 

• Current status of legal requirements and deadlines
• Available technologies for phosphorus recovery and their practical suitability
• Future capacities in thermal sewage sludge treatment and P recovery from ash
• Discussion of strategies and options for action with a view to the requirements of the Sewage Sludge Ordinance coming into force in 2029 

Join the discussion on how Germany can shape the path to sustainable phosphorus use!