This waste stream is connected to the technical Circular Solution "Energy recovery from the low calorific fraction (LCF) of a mechanical waste treatment plant".
Separately collected household and commercial organic waste, which is currently co-digested in WWTPs, will be treated in mono-digestion. The digestate will be dewatered, the solid residues composted and then used as a component for the production of a local horticulture substrate, for example to replace peat.
The composition of organic wastes in question is heterogeneous and varies according to commercial or private sources, seasons, and habitational structures. Usually, theses wastes have a high water content of > 50% for household and > 90% for commercial sources. An example of the appearance is given in Figure 3.
Figure 3: Appearance of commercial biowaste from separate collection
DM: < 10% – 50%, VS: 80% – > 90%, Contaminants (plastics, inert materials, others): < 20% – 0%
Biodigestion at WWTPs as co-substrate together with secondary sludge, dewatering, incineration, landfilling.
Biowastes from separate collection usually have few contaminants, most of which can be removed with existing technologies. In order to increase the overall degree of sustainability, these waste streams need to be treated separately and their nutrients and carbon recycled by agriculture and horticulture.