Germany’s municipal waste treatment plants processed around 1..32 million tons of sewage sludge in thermal treatment in 2023, a 1.2% decrease from the previous year, according to the Federal Statistical Office (Destatis) on Thursday.
This accounted for about 81% of the total 1.63 million tons of sewage sludge disposed of in 2023, a 2.2% decrease from the previous year. Around 226,000 tons were used in agriculture as fertilizer or in landscaping (14%), and 85,000 tons were disposed of through other methods (5%).
Industrial companies and municipal plants generated 473.8 million kilowatt-hours of electricity and 852.4 million kilowatt-hours of heat through the incineration of sewage sludge in 2023. Thermal treatment facilities, mainly sewage sludge incineration plants, played the most significant role, accounting for 49% of the thermally treated sewage sludge (648,000 tons).
The remaining 45% went into co-incineration, where sewage sludge was burned together with other materials, with 20% in coal-fired power plants or coal processing facilities (264,000 tons), 13% in cement plants (170,000 tons), and 12% in waste incineration plants (152,000 tons). The remaining 6% (78,000 tons) of sewage sludge was treated through other thermal methods.
Given the planned coal phase-out by 2038, it is expected that the incineration of sewage sludge in coal-fired power plants will decrease in the coming years. Cement plants use the ashes as fillers, while the ashes from waste incineration plants are mainly disposed of in landfills, with little reuse.
The Sewage Sludge Ordinance of 2017 set stricter guidelines for the use of sewage sludge in agriculture to reduce the entry of pollutants like pharmaceutical residues and microplastics into the soil. Starting in 2029, the mandatory recovery of phosphorus from sewage sludge will also be implemented to improve resource utilization.
In 2023, 656,000 tons of sewage sludge were incinerated in processes where, according to the current technical state, the recovery of phosphorus from the residues will be most efficient in the future, accounting for around 40% of the total sewage sludge disposed of. This is a 12% increase from the previous year.