Outotec constructed a thermal sewage sludge incineration facility in mid-2015 for the Disposal and Recycling Department of Zürich (ERZ).

The plant delivers minimal environmental emissions and maximises energy recovery and production of profitable by-products.

The Outotec sewage sludge incineration plant treats sewage sludge from over 70 wastewater treatment plants. Overall, the site is Switzerland’s largest thermal sewage sludge treatment facility, handling all the sludge produced in the Zürich canton area, amounting to 100,000 metric tonnes a year.

Sludge presents Zürich and other municipalities with several challenges. With limited landfill disposal possibilities and restrictions on its use as a fertiliser, as well as high transportation costs and strict emission limits, thermal incineration offers an excellent solution. In addition, by building a centralised sludge incineration plant, sludge disposal costs in the area are expected to be cut by almost half.

The Zürich plant operates with minimal environmental emissions, maximum recovery of energy and also offers the future benefit of retrofitting the Outotec ASH DEC process, which would convert the separated ash into phosphate fertilizer.

Benefits of Outotec sewage sludge incineration plants:

  • Self-sustaining thermal treatment
  • Minimal environmental emissions
  • Residue ash can be used for phosphorus recovery

Outotec supplied an EPC turnkey solution, including assistance with building permits and authority engineering. Outotec was also responsible for the complete engineering, construction, commissioning, and staff training on site.