Main-Tauber-Kreis is breaking new ground: Phosphorrele recovery starts in Würzburg!

Main-Tauber-Kreis is breaking new ground: Phosphorrele recovery starts in Würzburg!

In a pioneering initiative for sustainable use of raw materials, the Main-Tauber-Aisch Zweckverband sewage sludge recycling in Würzburg was founded on July 4, 2025. Around 40 municipalities from several counties are part of this project, which is particularly devoted to the recovery of phosphorus from sewage treatment plants. Mayor Markus Herrera Torrez from Wertheim has a special role because he represents eleven other municipalities from the Main-Tauber district. The agreement for the foundation was signed and approved in Wertheim at the end of April.

What does that mean for the region? The formation of this municipal composite system is an important step, because from 2029 the municipalities are legally obliged to regain phosphorus from sewage sludge. This regulation results from the regulation on the reorganization of the sewage sludge recycling (derogatory), which has been in force since September 27, 2017. The recovering obligation concerns the operator of sewage treatment plants and sewage sludge incineration plants, whereby the focus is particularly on sewage sludge, which has a phosphorus content of over 2 %. If more than 4 %, 50 % of the phosphorus must be recovered.

procedure for phosphorus recovery

In Würzburg, the sewage sludge is to be prepared in a new drying system. After this drying, the sewage sludge is burned in the Scheinfurt community power plant and then regained the valuable phosphorus from the ash. Overall, the counties involved-beyond the city of Werzheim and the Main-Tauber district, Würzburg, Kitzingen, Main-Spessart, Weißenburg-Gunzenhausen, Ansbach and Neustadt Aisch-Bad Windsheim-the preparation of up to 57,000 tons of drained sewage sludge annually.

Why is this step so important? Phosphorus is not only an essential nutrient for plants, but also for life as a whole, since it is a building block of DNA and ATP. In Germany, over 80 % of the phosphorus is used in fertilizers, and since the deposits are increasingly exhausted from these critical resources, the recovery from sewage sludge is traded as a significant solution. The Bavarian sewage sludge contains an average of 3.1 % phosphorus in the dry matter, and the annual amount in Bavaria is 270,000 mg TM.

• Average phosphorus content in the sewage sludge: 3.1 %
• Annual sewage sludge in Bavaria: approx. 270,000 mg TM/A
• phosphorus content in sewage sludge with <2 %: direct treatment necessary
• phosphorus content with> 4 %: 50 % recovery obligation
• for sewage sludge ash: 80 % of the phosphorus must be recovered

support and perspectives

The new guidelines and the establishment of the special -purpose association are not only a profit for the environment, but also offer economic opportunities. It can be assumed that the costs for phosphorus recovery are fitted to the wastewater fees. In view of the increasing demand for sustainable fertilizers, it could be good business. In addition, the upcoming adaptation of the fertilizer regulation should help to further promote phosphorus recyclates as fertilizer.

The initiative for phosphorrele recovery is also accompanied by an industry dialogue of the Federal Environment Ministry, which takes place in 2024 to analyze and eliminate obstacles in implementation. The region will not only benefit greatly through the collaboration, but also actively contributes to resource conservation and environmental protection.

Further information and current developments on the sewage sludge recycling and phosphorrele recruitment can be found at lfu.bayern.de and iwu-ev.de .