Post-Basin Effluent Equalization
Post-basin effluent equalization smoothes out flow variations prior to downstream processes, such as disinfection. By providing storage and a constant smooth flow, the disinfection process will be more effective. If post-flow equalization is not utilized, the effluent might not receive the designed amount of treatment. Post-basin effluent equalization also allows downstream processes to be sized smaller, since the flow from the
basin is metered out and does not hydraulically surge the downstream processes.
Effluent equalization also ensures that there are not large variations in operating ranges for the metering pumps and the chlorine analyzers. Ideally, the basin should be of sufficient size to hold a minimum of two decantable volumes. There should be a means of returning the liquid from the post-flow equalization basin to the headworks if a poor decant occurs. These basins should also have a means of removing solids from the bottom of the unit, such as a sloped bottom with a drain or sump.