The flow of water through the long rectangular sedimentation tank was analyzed by inject...

The flow of water through the long rectangular sedimentation tank was analyzed by injecting a pulse of a dye tracer in the influent. The concentrations of dye in the effluent at time intervals of 20 min starting from injection of the dye were as follows:

Draw a residence time distribution curve as shown in Figure 7-7b, locate the theoretical detention time of 120 min, and calculate and plot the mean residence time (centroid). (Answer t₅₀ = 96 min)