Method of biological removal of nitrogen and phosphor from waste water using segregated activated sludge compounds in a two-stage biological treatment plant

摘要

The invention relates to a method of biological removal of nitrogen and phosphor from waste water using segregated activated sludge compounds in a two-stage biological treatment plant, according to which in the first stage the incoming waste water (1) is merged with circulating sludge sediment (8), the resulting mix (7) is directed into intermediate sedimentation basin (6) from where clarified water (10) is led in the second stage through an oxic zone (11) into final sedimentation basin (13) where it is separated into active sludge sediment (14) and clarified water (15), whereas sediment (14) is led back to the oxic zone (11). Novelty lies in the use of segregated activated sludges in both stages and in clarified water (15) containing nitrates being led (17 or 18) from the final sedimentation basin (13) back to the anoxic zone (4), where the conversion of adenosine diphosphate into adenosine triphosphate takes place.