Home > Technical expertise > Sludge treatment

Sludge treatment

Sludge treatment and recycling

The sludge, which has been separated during the wastewater treatment process, is treated in the plant. The process employed drastically reduces the sludge volume. The volume of the sludge extracted from the wastewater is reduced by more than 99%. This means a much smaller quantity of sludge needs to be transported out of the plant by lorry.

In the treatment of the 275 million litres of wastewater which enter the plant daily, 60 tonnes of dry solids are produced. This volume is reduced to 15 tonnes of technosand upon exiting the plant.

Two complementary processes are used: digestion in anaerobic phase and wet oxidation.

Water and organic compounds are removed from the sludge by means of various treatments.

The sludge which has been treated with an additive is directed to the decanting tanks. After the decanting process it is mixed and centrifuged to eliminate as much water as possible. The centrifuges extract 15% of the water in the sludge.

The wastewater
treatment process


Read more

Bioplastic production in Brussels Green energy for blue water

Visit the plant

Guided tours of the Brussels-North wasterwater treatment plant are organised upon reservation.