Submitted by: Federal Institue for materials research
Implemented country: Germany
Title: Sustainable and Safe Reuse of Municipal Sewage Sludge
Because of its high content of organic and inorganic pollutants, the agricultural use of sludge is debatable and will decrease in the European Union. Therefore, its future disposal has to extract the contained nutrients, especially phosphorus, from the cycle (e.g., through disposal at the cement works and mono-combustion and subsequent landfill disposal). However, recycling the phosphorus makes good ecologic and economic sense and supports the protection of this nonrenewable resource. The project Susan is seeking a solution strategy where sludge is treated in mono-combustion plants and the resulting sludge ashes are educed to a marketable fertilizer that is rich in phosphorus. Mono-combustion destroys the organic pollutants. The heavy metal in the sludge ash is removed by a thermo-chemical procedure; simultaneously the availability of the phosphates is increased to 100%.