HUBER Pile Cloth Media Filter RotaFilt® as key component: five new flagship projects for the fourth treatment stage

A fourth treatment stage is currently being built at the sewage treatment works in Schwäbisch Hall, Markgröningen-Talhausen, Vörbach-Pfalzgrafenweiler and Meßkirch in Baden-Württemberg. These treatment works have opted for the GAC (German: GAK) process, which uses granulated activated carbon for adsorption. 

Upstream of the trace substance removal stages, there is a multi-stream pre-filtration system at each site, all of which have been equipped with the new HUBER Pile Cloth Media Filter RotaFilt®. These reliably protect the subsequent GAC‑adsorption process from dirt and contaminants, thereby ensuring stable and low-maintenance plant operation. In Vörbach-Pfalzgrafenweiler, twelve HUBER Activated Carbon Filter CONTIFLOW® GAK units are used as the GAC stage.

Trace substance removal and phosphorus removal

At the Eglosheim-Ludwigsburg wastewater treatment plant, powdered activated carbon is dosed directly into the biological stage to remove trace substances. Here, cloth filtration acts as a conventional final filtration stage and ensures that no loaded activated carbon particles from the secondary clarifier enter the receiving watercourse.

In all five projects, cloth filtration can also be operated in combination with coagulant dosing as flocculation filtration, should the most thorough possible removal of phosphorus be required.

Outlook and project status

All five plants are still under construction at present. The fourth-stage treatment facilities in Schwäbisch Hall and Eglosheim-Ludwigsburg are expected to be operational by 2026. The other projects are expected to be operational in 2027.