VERFAHREN UND VORRICHTUNG FÜR BIOLOGISCHE BEHANDLUNG

摘要

Effluent to be treated is introduced into the top of a first bioreactor (10) through an inlet pipe (16) and, after passing through second and third bioreactors (11 and 12), passes through a settling device (17), the treated effluent then flowing over a depth control weir (18) into an outlet pipe (19). The three bioreactors (10, 11 and 12) and the settling device (17) are housed in a tank having three sets of vertically-staggered transverse partitions (21, 22, 23) and a transverse settling tank partition (24). Each set of staggered partitions (21, 22 and 23) are arranged so that the bioreactors are interconnected in series, the effluent preferably being constrained to pass downwardly through each matrix (13, 14, 15) in turn against an upward discharge of very fine air bubbles from aeration panels (28) which extend under substantially the whole of each matrix. Aerobic bacteria feeds on nutrients in the effluent and grows on the roughened walls of the cross-flow matrix and the air bubbles promote sloughing of the bacteria. The apparatus therefore comprises three or more separate total mixed bioreactors working in sequence, each serving to reduce the biological oxygen demand of all the effluent whereby the biological oxygen demand is progressively reduced.