One important issue concerns questions around potential odor pollution. This can be 100 percent ruled out with the state-of-the-art plant: The combustion air is sucked out via a reception and storage bunker during operation of the plant, creating a vacuum, which, together with an airlock system, prevents odors from escaping outside.

Even if the plant is idle or out of service for an overhaul, the exhaust air is guided through a filter system. In such cases, odor pollution will also be reliably prevented.

Following storage, the sewage sludge is dried. Its water content is reduced to such an extent that it can be burned in an autothermal process in a so-called fluidized bed furnace at temperatures of up to 950 degrees Celsius. Organic matter is also completely incinerated at these temperatures.

Sewage sludge is already being incinerated and added to the fuel in coal power plants. Special incineration plants, such as those planned for Walheim, are notably superior to this method. For one thing, they are designed for low-emission processing (in other words, they significantly cut carbon emissions). Furthermore, the ash produced during incineration contains valuable phosphorus that can be recycled – as even required by legislators from 2029/2030. In modern plants, the ash containing the phosphorus can be better treated after the incineration process and then sent to specialized companies for further processing. As things currently stand, this is not possible when the sewage sludge is incinerated with other fuels in a coal power plant.