The applicability of tracer techniques for studies on sewage treatment process dynamics

Abstract

The applications of tracer techniques in studies of sewage treatment process dynamics are reviewed and discussed. Among the different tracer methods for flow-rate measurements, the dilution method is best applicable under sewage treatment plant conditions. In sedimentation basin studies, tracers have been used mainly in order to characterize the hydraulic efficiency of the basin. However, the practical value of these studies has been somewhat limited, because there is no explicit connection between the hydraulic behavior expressed in terms of the tracer test results and the solids removal efficiency. The unsteady character of sewage treatment processes creates difficulties in the application of tracer techniques. In the case of aeration basins having relatively steady flow patterns these difficulties are much slighter than in the case of sedimentation basins. The double-tracer method developed for the aeration capacity measurements under actual process conditions seems to have remarkable potential in aeration process development.