Bringest improvements to facilities and processes of biological purification of waste water including urban sewage

The present invention relates to biological treatment plants wastewater. This installation comprises: - one or more lagoons 1 anaerobic sludge bed arranged at the bottom, the or said lagoons being sealed by the application of a synthetic impermeable surface or membrane; - a distribution network 5 of the effluent to be treated placed on the bottom of the (or) lagoons (s) 1; - a cover for each lagoon, waterproof and gas, set on a frame or support taking support frame in the gutters 10 of the hydraulic belt also waterproofed; - discharge pipes gases 11, sludge 12 and purging outlet 14 of treated water, to lagoons infiltration including, - control and measuring instruments 13. (CF DRAWING IN BOPI)