Specific cleaning : Digesters

SEDE is equipped to carry out the emptying of digesters, whether for the sludge fraction or the sand fraction located at the bottom of the structure.

Wastewater is pumped and recycled by highly qualified personnel.

The operator does not work inside the digester, because emptying is performed once the structure has been inerted. The personnel operating at the site, however, have specific ATEX training.


Principle of digester emptying

The installation of a hydraulic pump in the middle of the structure allows the pulp containing sludge and sand, between 10 and 20% DM, to be suctioned.

The pulp at the bottom of the digester is cleaned and diluted using a powerful water cannon attached to the side manhole or dome. The extraction rate can be adapted from 100 to 160 m3/h. A vibrating screen is used to recover the inert fraction and a mobile pre-treatment/de-sanding unit is used to extract the mineral part of the pumped pulp (ecomobile). The equipment used for this is specifically adapted to the particular characteristics of the extracted pulp (sand and sludge).

The fine part can be returned to the station's dewatering line or processed by SEDE's mobile dewatering units.


Mobile sludge dewatering unit rental

Dewatering your by-products in order to valorise them via regulatory and adapted channels.



Digester cleaning in Angers

SEDE emptied and cleaned the digester of the Baumette Wastewater Treatment Unit in Angers.

The project lasted 16 weeks and required the installation of pumping and screening equipment, a mobile sand pre-treatment unit, dewatering equipment and conveyors, near the digester.

Recyclage des eaux usées : Vidange ou Curage de digesteurs


The volume of the digester to be cleaned was 9,000 m³, i.e.:




The materials were recovered, removed and treated via an approved channel (composting, WSF).

The service was carried out in complete safety by keeping human presence inside the digester to a strict minimum.