AMOUNT AND NATURE OF SOLUBLE REFRACTORY ORGANICS PRODUCED BY ACTIVATED-SLUDGE MICROORGANISMS IN SEQUENCING BATCH AND CONTINUOUS-FLOW REACTORS

Comparative experiments with a Sequencing Batch Reactor (SBR) and a co ntinuous flow activated sludge system have been conducted in bench-sca le to study factors affecting molecular composition and concentration of residual Soluble Microbial Products (SMP). It was experimentally co nfirmed that the amount of SMP in secondary effluents depends on appli ed process conditions, in particular on sludge age, hydraulic detentio n time distribution and concentration gradients within the bioreactor. The residual SMP consist of both low and high molecular organic compo unds. The former prevail. The continuous now system with a completely mixed aeration tank produced consistently higher concentrations of SMP than the SBR The lowest SMP concentration was found at sludge ages be tween 5 and 15 days. Copyright (C) 1996 IAWQ.