4. Thermal removal techniques

These techniques encompass all processes used to break down all or part of the organic matter contained in the sludge. They are therefore particularly well-suited for organic, carbon-rich sludge.

However, sludge with a high mineral content can also be treated by incineration, typically with the use of a supplementary fuel. The purpose of this treatment is to reduce the residual organic content, lower the moisture content, or concentrate certain pollutants.

Thermal oxidation takes place in the gas phase at high temperatures (above 850 °C, in accordance with regulations), using an excess of air; this process is referred to as "incineration."

This operation can be performed:

• in a dedicated incinerator located on the wastewater treatment plant site (“stand-alone incineration”),...