The biodegradation of morpholine in river water and activated sludge

Abstract

The ability of microorganisms in a wide range of river waters and activated sludges to degrade the heterocyclic compound morpholine was determined by die-away tests and also by most probable number counts of the morpholine degrading microbes. All activated sludges were capable of morpholine degradation but the rate at which degradation occurred could not be related to the type of influent treated. Nearly all river waters contained morpholine degrading microbes which could degrade morpholine in die-away tests. Generally, biodegradation of morpholine occurred more rapidly the further down stream the sample was taken. Morpholine degradation rates could not, however, be related to the immediate severity of pollution (as measured by National Water Council (NWC) classification) at any sampling site. It may be that morpholine degradation rate is related to the cumulative effects of successive discharges of polluting effluents rather than the immediate effect of any particular discharge. Clearly, the capacity to degrade morpholine exists in rivers and activated sludges from sewage works; in practice, however, the rates of degradation observed are very low and it is unlikely that significant morpholine biodegradation generally occurs in these systems.