Technical Bulletin No. 0408: A Review of Procedures for Conducting ConservativeTracer Studies in Hydraulic Characterization Effluent Treatment Basins – Parts I and II

An important aspect of the National Council's program dealing with upgrade options for forest products industry effluent treatment systems focuses on the impact of mixing regime and hydraulic residence time on the performance of activated sludge and aerated stabilization basin systems. Tracer selection, application, sampling and analysis protocols and the interpretation of the tracer curve for wastewater treatment system evaluation are the subjects of this two part bulletin. The bulletin covers both the theoretical and practical aspects of using conservative tracers, such as lithium, to judge the mixing regime existing within an aerated basin; the results of a tracer study were also used to calibrate the hydraulic portion of one of NCASI's wastewater treatment plant models which was then used to determine if altering the mixing regime would improve BOD removal.