Limnosolids® – Sewage Sludge Treatment

Limnosolids® is a passive approach technology of reed beds enabling dehydration, mineralisation and stabilisation of sludge from wastewater treatment plants. It is using only natural processes.

The technology enables long-term and sustainable storage of sludge with low operating and maintenance costs. It can completely replace dehydration which currently represents significant cost on existing wastewater treatment plants.

With this technology different types of sewage and industrial sludge can be treated. It is stored in the reed beds normally between 8 to 10 years. Due to parallel operation of physical (drying) and biological processes (mineralisation) the treatment results in significant sludge volume reduction. The sludge no longer contains pathogen organisms and is therefore stabilised.

The end result of the process is a compost-like soil that can be reused as fertilizer in agriculture, cover layer for landfills or construction material.

Scheme of Limnosolids® operation

Our services can be complete or partial but always customer oriented:

  • elaboration of final project design,
  • construction, surveillance of construction and performance optimisation,
  • training of facility operating staff,
  • elaboration of operation and maintenance manual.

1. Sludge Loading

  • Aerobic conditions and sludge drying
  • Pulse loading of reed beds with resting periods

2. Loading Complete

  • Conversion to humus like (bio)material
  • Long-term sludge accumulation and storage (8 to 10 years)

3. Biosolids Excavation
and reuse

  • Volume reduction of 95 %
  • Source of nutrients (N, P)

4. New Loading Cycle

  • Start of a new operational cycle
  • Re-planting of plants is not necessary

Low cost

Compared to other sludge treatment technologies costs are considerably lower.


Treated sludge is not waste but becomes material for reuse.

Chemical free

The system operates without using chemicals, such as polymers or flocculants.


Not only is the sludge dehydrated, but is also stabilised (contains no pathogen bacteria).