The mechanical-biological waste treatment (MBT) is material-specific waste treatment which can be recycled from a material and energetic point of view.
The waste which is treated is refuse from households and companies (household waste or household-like industrial waste and green waste).
The following waste fractions can be produced during the treatment process:
- Waste for material recovery
- Waste for energetic recovery
- Waste for thermal treatment
- Waste for biological treatment and subsequent landfill
THE OBJECTIVES OF MECHANICAL-BIOLOGICAL WASTE TREATMENT ARE:
- Reduce the volume of the waste to be dumped and thus preserve the required landfill volume.
- Reduce the biological activity of the organic fraction in the household waste such that as little landfill gas as possible can escape in an uncontrolled manne on the dumpsite.
- Minimize the harmful substances which may enter the groundwater together with the leachate.
Miscellaneous process steps treat the input material, e.g. the material is crushed for coarse primary sorting. It is then screened to divide the material to form several material flows, subjected to separation of ferrous and non-ferrous metals and, if required, to a manual sorting process to divide the fractions to coarse, medium and fine fractions. The coarse fraction contains film, paper, hard plastics, wood etc. which is separated from heavy and interfering material again. They will be disposed of separately.
This produces a highly calorific fraction which can be used as fuel in SF power plants. The fine fraction is conveyed to the biological section of the plant where the material is subjected to a further anaerobic treatment by a composting process, significantly reducing the organic substances.
The biological activity is complied with according to the specified parameters of the respective country. The equipment of the MBT and the pertaining division degree of the material flows depend on the specifications of the country's waste respective management system.