Specific drainage or cleaning : Digesters

SEDE is equipped to drain digesters, whether the sludge fraction or the sandy fraction located at the bottom of the structure.

Wastewater pumping and recycling is carried out by highly qualified personnel.

The operator does not work inside the digester, because this latter is emptied after the structure has been inerted. Staff operating on-site, however, have specific ATEX training.


Digester emptying principle

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 sucked up.

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.

curage de digesteur

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 taken over by the mobile dewatering units.


Mobile sludge dewatering unit rental

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




Digester cleaning in Angers

SEDE drained 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.

2,200 tonnes of dewatered sludge

400 tonnes of sand

500 tonnes of fibres

The materials were recovered, removed and treated in an approved channel (composting, ISD).

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