Sludge digestion

Anaerobic digestion reduces the weight (dry matter) of sludge. Digestion also aims to stabilise the organic matter in order to reduce olfactory nuisances and to produce recoverable energy in the form of biogas.
Objectives

To reduce the quantity of sludge and produce energy

Faced with the rise in the production of sludge and the increasing difficulty in eliminating it (costs, regulations), SUEZ implements techniques that reduce the volume of the sludge and recover biogas.

The anaerobic digestion processes developed by SUEZ offer a number of advantages:

 

Reduced quantities of sludge
Depending on the process used, volumes can be reduced by up to 50%.


Increased dry content 
Certain innovative processes can increase the dry content by 5 to 10 points compared with conventional digestion.


Long-term stabilisation 
Sludge conditioning reduces olfactory nuisances and encourages hygienation.


Recovery of the sludge as green energy by producing biogas
SUEZ offers innovative technologies that can as much as double the production of recoverable biogas compared with conventional digestion.

Processes

Developing innovative technologies for sludge digestion

SUEZ can offer proven processes that are constantly improved and that effectively meet your need to digest the sludge produced by the treatment of wastewater.

Depending on the quantity and the nature of the sludge (biological, mixed, etc.), different types of digestion are possible:

  • mesophilic digestion at 37°C
  • Digelis Smart: integrated mesophilic digestion and biogas storage
    Digelis Smart combines sludge digestion and the storage of biogas to offer a compact, practical and economical solution.
  • thermophilic digestion at 55°C
  • Digelis Duo: thermophilic digestion at 55°C combined with mesophilic digestion at 37°C
  • Digelis Fast: thermophilic digestion at 55°C
  • Digelis Turbo: thermal hydrolysis combined with mesophilic digestion at 37°C
    Digelis Turbo halves the quantity of sanitized sludge and increases the production of recoverable biogas.