BIOREACTOR FOR TREATING EFFLUENTS BY AN AERATING CHANNEL

摘要

A bioreactor for treating urbane or industrial effluents by an activated sludge comprises a closed, in particular annular, circuit aerating channel (2),, in which an activated sludge is circulated by at least one agitator (3) at a speed sufficient for maintaining a homogenous concentration along the totality of the channel height and aerating systems (a) arranged on the channel bottom for oxygenating an incoming biomass. The inventive bioreactor comprises an assembly (E) of filtering membranes (5) arranged upstream of the agitator (3) wherein said filtering membranes are immersed into the channel sludge (B) and the low part thereof is positioned at a distance from the channel bottom, a screen (S) which is placed upstream of said filtering membranes (5) at a sufficiently small distance (j) in such a way that the membranes are protected against a sludge flow, and additional circulation means (11) comprising a rapid agitator (12) located in the low part of the channel immediately upstream of the membranes (5) for facilitating the sludge flow passage under the membrane assembly (E) and for compensating a loss of charge caused by the presence of membranes (E) and the protective screen (S).