4. Thermal elimination techniques

These techniques cover all processes that degrade all or part of the sludge's organic matter. They are therefore preferentially applied to carbon-rich organic sludge.

However, predominantly mineral sludge can be "burnt" in the presence of fuel to reduce its residual organic fraction, its water content or to concentrate its pollutants.

• Thermal oxidation can take place in the gaseous phase, at high temperature (above 850°C according to regulations) with excess air, and is then referred to as "incineration". This can take place :

  • in a specific incinerator located on the treatment plant site ("solo" incineration), a solution to be adopted for large tonnages, at least of the order of ten t MS/d ;

  • in an off-site incinerator, i.e. co-incinerated...