The focus is on sustainable sludge treatment, cost reduction and the use of nutrients in sewage sludge. Together with local partners, an innovative approach has been developed that enables the resource-saving and economical use of sewage sludge as a soil fertilizer. At the same time, Tilia is working on the energy efficiency of sewage treatment plants, for example by optimizing operations and generating its own energy.

Time period:

• Since 2015

Objectives:

• Improvement of sludge treatment and disposal
• Use of nutrients in sewage sludge as sustainable soil fertilizer
• Reduction of operating costs
• Increasing the energy efficiency of wastewater treatment plants

Key steps:

• • Sludge analysis:
    Confirmation of harmlessness and suitability for agricultural use.
  • Proof: No pollutants such as heavy metals, sufficient nutrients.
  • Technical solution:
    Development of a low-tech approach (“Terra Preta”) to convert and sanitize the sludge into fertilizer.
  • Profitability analysis to assess market opportunities.
  • Implementation:
    Production of soil fertilizer from sewage sludge.
  • Involvement of local partners and increase in resource efficiency.
  • Energy efficiency:
    Optimization of plant operation (e.g. O₂ control, pumps).
    Installation of photovoltaic systems with storage.

Result:

• Improvement in the local use of resources.
• Economic and ecological added value for municipalities.